TIME SPEED DISTANCE EXAMPLE QUESTIONS PART 1

TIME SPEED DISTANCE EXAMPLE QUESTIONS PART 1

1)A person crosses a 600 m long street in 5 minutes. What is his speed in km per hour?

 

A.3.6

B.7.2

C.8.4

D.10

Answer: Option B

 

Explanation:

 

Speed = (600) / (5 x 60) m/sec

   = 2 m/sec.

 Converting m/sec to km/hr

   =2 x (18 / 5)km/hr

   = 7.2 km/hr.

 

2)A man on tour travels first 160 km at 64 km/hr and the next 160 km at 80 km/hr. The average speed for the first 320 km of the tour is

 

A) 35.55 km/hr 

B) 36 km/hr

C) 71.11 km/hr  

D) 71 km/hr

Answer & ExplanationAnswer: C) 71.11 km/hr

 

Explanation:

Total time taken    = (160/64 + 160/8)hrs

                           = 9/2 hrs.

 Average speed    = (320 x 2/9) km.hr

                         = 71.11 km/hr.

 

3)Two trains A and B start simultaneously in the opposite direction from two points P and Q and arrive at their destinations 16 and 9 hours respectively after their meeting each other. At what speed does the second train B travel if the first train travels at 120 km/h

 

A) 90 km/h          B) 160 km/h

C) 67.5 km/h       D) None of these

 Answer & ExplanationAnswer: B) 160 km/h

 

Explanation:

           _____

s1 / s2 = √t2/t1

           ____

⇒120/s2 = √9/16=3/4

⇒s2 = 160km/h

 

4)How long will a boy take to run round a square field of side 35 meters, If he runs at the rate of 9 km/hr?

 

A) 50 sec             B) 52 sec

C) 54 sec              D) 56 sec

 Answer & ExplanationAnswer: D) 56 sec

 

Explanation:

Speed = 9 km/hr = 9 x (5/18) m/sec = 5/2 m/sec  

 Distance = (35 x 4) m = 140 m.

 Time taken = 140 x (2/5) sec= 56 sec

 

5)The speed of a car increases by 2 kms after every one hour. If the distance travelling in the first one hour was 35 kms. what was the total distance travelled in 12 hours?

 

A) 456 kms          B) 482 kms

C) 552 kms          D) 556 kms

 Answer & ExplanationAnswer: C) 552 kms

 

Explanation:

Total distance travelled in 12 hours =(35+37+39+.....upto 12 terms)

This is an A.P with first term, a=35, number of terms,

n= 12,d=2.

Required distance    = 12/2[2 x 35+{12-1) x 2]

=6(70+23)

= 552 kms.

 

6)Two horses start trotting towards each other, one from A to B and another from B to A. They cross each other after one hour and the first horse reaches B, 5/6 hour before the second horse reaches A. If the distance between A and B is 50 km. what is the speed of the slower horse?

 

A) 30 km/h          B) 15 km/h

C) 25 km/h          D) 20 km/h

 Answer & ExplanationAnswer: D) 20 km/h

 

Explanation:

If the speed of the faster horse be fs and that of slower horse be ss then

 fs+ss=50/1=50

 and       50/ss−50/fs=5/6

Now, you can go through options.

 The speed of slower  horse is 20km/h

 Since,   20+30=50

 and  50/20−50/30 = 5/6

 

7)A man takes 6 hours 15 minutes in walking a distance and riding back to the starting place. He could walk both ways in 7 hours 45 minutes. The time taken by him to ride both ways, is

 

A) 4 hours           B) 4 hours 30 minutes

C) 4 hours 45 minutes     D) 5 hours

 Answer & ExplanationAnswer: C) 4 hours 45 minutes

 

Explanation:

Time taken in walking both ways = 7 hours 45 minutes                     --------(i)

 Time taken in walking one way and riding back= 6 hours 15 minutes-------(ii)

 By equation (ii)*2 -(i), we have

 Time taken to man ride both ways, = 12 hours 30 minutes - 7 hours 45 minutes

= 4 hours 45 minutes

8) A man walking at the rate of 5 km/hr crosses a bridge in 15 minutes. The length of the bridge (in metres) is

 

A) 600   B) 750

C) 1000 D) 1250

 Answer & ExplanationAnswer: D) 1250

 

Explanation:

speed    = (5x5/18)m/sec

             = 25/18 m/sec.

Distance covered in 15 minutes = (25/18 x 15 x 60)m

                               = 1250 m. 

 

9)A man reaches his office 20 min late, if he walks from his home at 3 km per hour and reaches 30 min early if he walks 4 km per hour. How far is his office from his house ?

 

A) 20 km              B) 16 km

C) 14 km              D) 10 km

 Answer & ExplanationAnswer: D) 10 km

 

Explanation:

Let distance = x km.

Time taken at 3 kmph : dist/speed = x/3 = 20 min late.

time taken at 4 kmph : x/4 = 30 min earlier

difference between time taken : 30-(-20) = 50 mins = 50/60 hours.

x/3- x/4 = 50/60

x/12 = 5/6

x = 10 km.

 

10)The distance between two cities A and B is 330 Km. A train starts from A at 8 a.m. and travel towards B at 60 km/hr. Another train starts from B at 9 a.m and travels towards A at 75 Km/hr. At what time do they meet?

 

A) 10 a.m            B) 10.30 a.m

C) 11 a.m             D) 11.30 a.m

 Answer & ExplanationAnswer: C) 11 a.m

 

Explanation:

Suppose they meet x hrs after 8 a.m

 then,

 [Distance moved by first in x hrs] + [Distance moved by second in (x-1) hrs] = 330.

 Therefore, 60x + 75(x-1) = 330.

 => x=3.

 So,they meet at (8+3) i.e, 11a.m

 

11)Two persons start running simultaneously around a circular track of length 300 m from the same point at speeds of 15 km/hr and 25 km/hr. When will they meet for the first time any where on the track if they are moving in opposite directions  ?

 

A) 27 sec             B) 31 sec

C) 23 sec              D) 29 sec

 Answer & ExplanationAnswer: A) 27 sec

 

Explanation:

Time taken to meet for the first time anywhere on the track

 = length of the track / relative speed

 = 300 / (15 + 25)5/18 = 300x 18 / 40 x 5 = 27 seconds.

 

12)The ratio between the speeds of two trains is 7: 8. If the second train runs 400 kms in 4 hours, then the speed of the first train is ?

 

A) 83.5 km/hr     B) 84.5 km/hr

C) 86.5 km/hr     D) 87.5 km/hr

 Answer & ExplanationAnswer: D) 87.5 km/hr

 

Explanation:

Let the speeds of two trains be 7X and 8X km/hr.

 8x = 400/4

 => x= 12.5 km/hrX=4004=>X=12.5Km/hr

 So speed of first train is 12.5*7 = 87.5 km/hr

 

13)A train overtakes two girls who are walking in the  opposite direction in which the train  is going at the rate of 3 km/h and 6km/h and passes them completely in 36 seconds and 30 seconds respectively. The length of the train is:

 

A) 120m               B) 150m

C) 125m               D) None of these

 Answer & ExplanationAnswer: B) 150m

 

Explanation:

Let the length of the train e x meter, and let the speed of train be y km/h, then

 x=(y+3)× (5/18)×36   --------(1)   and  

 x=(y+6)× (5/18)×30  ---------(2)

 From eq (1) and (2), we get     

 y = 12 km/h

 Therefore,  x=(y+3)×(5/18)×36   =>  x= 150 m

 

14)An employee may claim Rs. 7.00 for each km when he travels by taxi and Rs. 6.00 for each km if he drives his own car. If in one week he claimed Rs. 595 for traveling 90 km. How many kms did he travel by taxi ?

 

A) 55 kms            B) 35 kms

C) 25 kms            D) 65 kms

 Answer & ExplanationAnswer: A) 55 kms

 

Explanation:

Let x and y be the respective km's travelled by man via taxi and by his own car.

Given x + y = 90 => x = 90 - y

But according to the question,

7x + 6y = 595

7(90-y) + 6y = 595

=> 630 - 7y + 6y = 595

=> y = 630 - 595 = 35

=> x = 90 - 35 = 55

Therefore, the distance travelled by taxi is 55 kms.

 

15)With an average speed of 40 km/hr, a train reaches its destination in time. If it goes with an average speed of 35 km/hr, it is late by 15 minutes. Find the length of the total journey?

 

A) 70 kms            B) 60 kms

C) 45 kms            D) 30 kms

 Answer & ExplanationAnswer: A) 70 kms

 

Explanation:

Let the time taken by train be 't' hrs.

Then,

40t = 35(t + 15/60)

40t = 35t + 35/4

 t = 7/4 hrs

 Therefore, Required length of the total journey d = s x t

 = 40 x 7/4

 = 70 kms.

 

16)A person goes to his office at 1/3rd of the speed at which he returns from his office. If the average speed during the whole trip is 12 m /h . what is the speed of the person while he was going to his office?

 

A) 10      B) 6

C) 8        D) can't be determined

 Answer & ExplanationAnswer: C) 8

 

Explanation:

u = k , v= 3k

 ∴2uv / u+v ⇒2×k×3k / (k+3k)=12  => k = 8km/h

 

17)A train covers a distance in 50 minutes, if it runs at a speed of 48kmph on an average. Find the speed at which the train must run to reduce the time of journey to 40 minutes.

 

A) 50 km/hr        B) 60 km/hr

C) 65 km/hr         D) 70 km/hr

 Answer & ExplanationAnswer: B) 60 km/hr

 

Explanation:

We are having time and speed given, so first we will calculate the distance. Then we can get new speed for given time and distance.

Lets solve it.

 

Time = 50/60 hr = 5/6 hr

Speed = 48 mph

Distance = S*T = 48 * 5/6 = 40 km

 

New time will be 40 minutes so,

Time = 40/60 hr = 2/3 hr

Now we know,

Speed = Distance/Time

New speed = 40*3/2 kmph = 60kmph

 

18)A Person X started at 3 hours earlier  at 40km/h from a place P, then another person Y followed him at 60km/h. Started his journey at 3 O'clock, afternoon. What is the diference in time when X was30 km ahead of Y and when Y was 30 km ahead of X?

 

A) 2h      B) 3h

C) 3.5h  D) 4.25h

 Answer & ExplanationAnswer: B) 3h

 

Explanation:

Time ( when X was 30 km ahead of Y) = (120-30)/20 =4.5h

 Time ( when Y was 30 km ahead of X) = (120+30)/20 = 7.5 h

 Thus, required  difference in time = 3h

 

19)A man whose speed is 4.5 kmph in still water rows to a certain upstream point and back to the starting point in a river which flows at 1.5 kmph, find his average speed for the total journey ?

 

A) 5 kmph            B) 7 kmph

C) 3 kmph            D) 4 kmph

 Answer & ExplanationAnswer: D) 4 kmph

 

Explanation:

Speed of Man = 4.5 kmph

Speed of stream = 1.5 kmph

Speed in DownStream = 6 kmph

Speed in UpStream = 3 kmph

Average Speed = (2 x 6 x 3)/9 = 4 kmph.

 

20)Two bike riders ride in opposite directions around a circular track, starting at the same time from the same point. Biker A rides at a speed of 16 kmph and biker B rides at a speed of 14 kmph. If the track has a diameter of 40 km, after how much time (in hours) will the two bikers meet?

 

A) 6.52  B) 8.14

C) 4.18  D) 5.02

 Answer & ExplanationAnswer: C) 4.18

 

Explanation:

Distance to be covered = πD = 40π km

 Relative speed of bikers = 16 + 14 = 30 kmph.

 Now, time=distance / speed =  40π / 30 = 4.18 hrs

 

21)A person takes 20 minutes more to cover a certain distance by decreasing his speed by 20%. What is the time taken to cover the distance at his original speed ?

 

A) 1hr    B) 1 hr 20 min

C) 1 hr 10 min    D) 50 min

 Answer & ExplanationAnswer: B) 1 hr 20 min

 

Explanation:

Let the distance and original speed be 'd' km and 'k' kmph respectively.

 d/0.8k - d/k = 20/60 => 5d/4k - d/k = 1/3

 => (5d - 4d)/4k = 1/3 => d = 4/3 k

 Time taken to cover the distance at original speed

 = d/k = 4/3 hours = 1 hour 20 minutes

 

22)P is faster than Q. P and Q each walk 24 km. The sum of their speeds is 7 km/hr and the sum of times taken by them is 14 hours. Then, P's speed is equal to ?

 

A) 3 km/hr           B) 4 km/hr

C) 5 km/hr           D) 6 km/hr

 Answer & ExplanationAnswer: B) 4 km/hr

 

Explanation:

Let P's speed = x km/hr. Then, Q's speed = (7 - x) km/ hr.

 So, 24/x + 24/(7 - x) = 14

 x^2-98x +168=0

 (x - 3)(x - 4) = 0 => x = 3 or 4.

 Since, P is faster than Q,

 so P's speed = 4 km/hr and Q's speed = 3 km/hr.

 

23)A man in a train notices that he can count 41 telephone posts in one minute. If they are known to be 50 metres apart, then at what speed is the train travelling?

 

A) 60 km/hr        B) 100 km/hr

C) 110 km/hr      D) 120 km/hr

 Answer & ExplanationAnswer: D) 120 km/hr

 

Explanation:

Number of gaps between 41 poles = 40

So total distance between 41 poles = 40*50

= 2000 meter = 2 km

In 1 minute train is moving 2 km/minute.

Speed in hour = 2*60 = 120 km/hour

 

24)Two men A and B start from place X walking at 4 ½ kmph and 5 ¾ kmph respectively. How many km apart they are at the end of 3 ½ hours if they are walking in the same direction ?

 

A) 2 9/7 km         B) 3 7/5 km

C) 1 3/4 km         D) 4 3/8 km

 Answer & ExplanationAnswer: D) 4 3/8 km

 

Explanation:

Relative Speed = 5 ¾ - 4 ½ = 1 ¼

 Time = 3 ½ h.

Distance = 5/4 x 7/2 = 35/8 = 4 3/8 km.

 

25)Excluding stoppages, the average speed of a bus is 60 km/hr and including stoppages, the average speed of the bus is 40 km/hr. For how many minutes does the bus stop per hour ?

 

A) 2 hrs B) 20 min

C) 40 min             D) 30 min

 Answer & ExplanationAnswer: B) 20 min

 

Explanation:

In 1hr, the bus covers 60 km without stoppages and 40 km with stoppages.

 Stoppage time = time take to travel (60 - 40) km i.e 20 km at 60 km/hr.

 stoppage time = 20/60 hrs = 20 min.

 

26)A man covers a distance of 1200 km in 70 days resting 9 hours a day, if he rests 10 hours a day and walks with speed 1½ times of the previous in how many days will he cover 840 km ?

 

A) 39 days           B) 37 days

C) 35 days           D) 33 days

 Answer & ExplanationAnswer: C) 35 days

 

Explanation:

Distance d = 1200km

let S be the speed

 he walks 15 hours a day(i.e 24 - 9)

so totally he walks for 70 x 15 = 1050hrs.

 

S = 1200/1050 => 120/105 = 24/21 => 8/7kmph

given 1 1/2 of previous speed

so 3/2 * 8/7= 24/14 = 12/7

 New speed = 12/7kmph

 Now he rests 10 hrs a day that means he walks 14 hrs a day.

 time = 840 x 7 /12 => 490 hrs

=> 490/14 = 35 days

 So he will take 35 days to cover 840 km.

 

27)Two trains starting at the same time from two stations 200 km apart and going in opposite directions cross each other at a distance of 110 km from one of the stations. What is the ratio of their speeds?

 

A) 9 : 20               B) 11 : 9

C) 11 : 20             D) None of these

 Answer & ExplanationAnswer: B) 11 : 9

 

Explanation:

In the same time, they cover 110 km and 90 km respectively.

 Therefore, Ratio of their speeds = 110 : 90 = 11 : 9

 

28)A man covered a certain distance at some speed. Had he moved 3 kmph faster, he would have taken 40 minutes less. If he had moved 2 kmph slower, he would have taken 40 minutes more. The distance (in km) is

 

A) 30      B) 36

C) 40      D) 42

 Answer & ExplanationAnswer: C) 40

 

Explanation:

Let distance = x km and usual rate = y kmph.

Then, x/y - x/(y+3) = 40/60 --> 2y (y+3) = 9x ----- (i)

Also, x/(y-2) - x/y = 40/60 --> y(y-2) = 3x -------- (ii)

On dividing (i) by (ii), we get:

 

x = 40 km.

 

29)A thief goes away with a MARUTHI car at a speed of 40 kmph. The theft has been discovered after half an hour and the owner sets off in a bike at 50 kmph when will the owner over take the thief from the start ?

 

A) 2 hrs 10 min  B) 2 hrs

C) 2 hrs 5 min     D) 2 hrs 30 min

 Answer & ExplanationAnswer: B) 2 hrs

 

Explanation:

|-----------20--------------------|

50                           40

 Difference = 20kms

 Relative Speed = 50 – 40 = 10 kmph

 Time = 20/10 = 2 hours.

 

30)Jagan went to another town covering 240 km by car moving at 60 kmph. Then he covered 400km by train moving at 100 kmph and then rest 200 km he covered by a bus moving at 50 kmph. The average speed during the whole journey was ?

 

A) 36 kmph         B) 35 kmph

C) 72 kmph          D) 70 kmph

 Answer & ExplanationAnswer: D) 70 kmph

 

Explanation:

By car 240 km at 60 kmph

Time taken = 240/60 = 4 hr.

 By train 240 km at 60 kmph

Time taken = 400/100 = 4 hr.

 By bus 240 km at 60 kmph

Time taken = 200/50 = 4 hr.

 So total time = 4 + 4 + 4 = 12 hr.

and total speed = 240+400+200 = 840 km

Average speed of the whole journey = 840/12 = 70 kmph.

 

31)A man walks at a speed of 2 km/hr and runs at a speed of 6 km/hr. How much time will the man require to cover a distance of 20 1/2 km, if he completes half of the distance, i.e., (10 1/4) km on foot and the other half by running ?

 

A) 12.4 hrs          B) 11.9 hrs

C) 10.7 hrs           D) 9.9 hrs

 Answer & ExplanationAnswer: B) 11.9 hrs

 

Explanation:

We know that

 Time = Distance/speed

Required time = (10 1/4)/2 + (10 1/4)/6

= 41/8 + 41/6

= 287/24 = 11.9 hours.

 

32)A and B runs around a circular track. A beats B by one round or 10 minutes. In this race, they had completed 4 rounds. If the race was only of one round, find the A's time over the course:

 

A) 8 min               B) 7.5 min

C) 12.5 min         D) 12 min

 Answer & ExplanationAnswer: B) 7.5 min

 

Explanation:

B runs around the track in 10 min.

 i.e ,    Speed of B = 10 min per round

 Therefore,  A beats B by 1 round

 Time taken  by A to complete 4 rounds

   = Time taken by B to complete 3 rounds 

 = 30 min

 Therefore, A's speed = 30/4 min per round = 7.5 min per round

 Hence, if the race is only of one round A's time over the course = 7 min 30 sec

 

33)A train of length 250 m crosses a bridge of length 150m in 20 seconds. What is the speed of train?

 

 Answer

Sol : (length of train+ length of bridge) = speed of train x Time

 (250+150) = 20 x Speed

     Speed = 400/20= 20 m/s =72 km/h

 

34)Mr. Karthik drives to work at an average speed of 48 km/hr. Time taken to cover the first 60% of the distance is 20 minutes more than the time taken to cover the remaining distance. Then how far is his office ?

 

A) 40 km              B) 50 km

C) 70 km              D) 80 km

 Answer & ExplanationAnswer: D) 80 km

 

Explanation:

Let the total distance be 'x' km.

Time taken to cover remaining 40% of x distance is   t1=40 × x / 100×48

But given time taken to cover first 60% of x distance is   t2=t1+(20/60)hrs

 t2=60 × x / 100×48

∴60×x / 100×48= (40×x / 100×48)+20/60

 x=80 km.

 

35)Two persons start running simultaneously around a circular track of length 600 m from the same point at speeds of 25 kmph and 35 kmph. When will they meet for the first time any where on the track  ?

 

A) 54 sec             B) 36 sec

C) 72 sec              D) 11 sec

 Answer & ExplanationAnswer: B) 36 sec

 

Explanation:

Time taken to meet the first time = length of track/relative speed

 

Given the length of the track is 600 m

The relative speed = 25 + 35 = 60 kmph = 60 x 5/18 m

 Therefore Time = 600 / (25+35)(5/18)= 600/60 x (18/5) = 36 sec.

 

36)A bus covers its journey at the speed of 80km/hr in 10hours. If the same distance is to be covered in 4 hours, by how much the speed of bus will have to increase ?

 

A) 85 km/hr        B) 95 km/hr

C) 105 km/hr      D) 120 km/hr

 Answer & ExplanationAnswer: D) 120 km/hr

 

Explanation:

Initial speed = 80km/hr

Total distance = 80 x 10 = 800km

New speed = 800/4 =200km/hr

Increase in speed = 200 - 80 = 120km/hr

 

37)Robert is traveling on his cycle and has calculated to reach point A at 2 p.m. if he travels at 10 km/hr; he will reach there at 12 noon if he travels at 15 km/hr. At what speed must he travel to reach A at 1 p.m. ?

 

A) 20 kmph         B) 18 kmph

C) 12 kmph          D) 16 kmph

 Answer & ExplanationAnswer: C) 12 kmph

 

Explanation:

Let the distance traveled be x km.

Then, x/10 - x/15 = 2

3x - 2x = 60 => x = 60 km.

Time taken to travel 60 km at 10 km/hr = 60/10 = 6 hrs.

So, Robert started 6 hours before 2. p.m. i.e., at 8 a.m.

Required speed = 60/5 = 12 kmph.

 

38)K and L starts walking towards each other at 4 pm at speed of 3 km/hr and 4 km/hr respectively. They were initially 17.5 km apart. At what time do they meet ?

 

A) 6:00 am          B) 6:30 pm

C) 5:45 am          D) 5:52 pm

 Answer & ExplanationAnswer: B) 6:30 pm

 

Explanation:

Suppose they meet after 'h' hours

 Then

 3h + 4h = 17.5

7h = 17.5

h = 2.5 hours

 So they meet at => 4 + 2.5 = 6:30 pm

 

39)Two motor bikes cover the same distance at the speed of 60 and 64 kmps respectively. Find the distance traveled by them if the slower bike takes 1 hour more than the faster bike ?

 

A) 1102 km         B) 1060 km

C) 960 km            D) 1250 km

 Answer & ExplanationAnswer: C) 960 km

 

Explanation:

60(x + 1) = 64x

 X = 15

 60 x 16 = 960 km

 

40)A person travels from K to L a speed of 50 km/hr and returns by increasing his speed by 50%. What is his average speed for both the trips ?

 

A) 55 kmph         B) 58 kmph

C) 60 kmph          D) 66 kmph

 Answer & ExplanationAnswer: C) 60 kmph

 

Explanation:

Speed on return trip = 150% of 50 = 75 km/hr.

 Average speed = (2 x 50 x 75)/(50 + 75) = 60 km/hr.

 

41)P, Q and R start simultaneously from A to B. P reaches B, turns back and meet Q at a distance of 11 km from B. Q reached B, turns back and meet R at a distance of 9 km from B. If the ratio of the speeds of P and R is 3:2, what is the distance between A and B ?

 

A) 99      B) 100

C) 89      D) 1

 Answer & ExplanationAnswer: A) 99

 

Explanation:

Let, Distance between A and B = d

 Distance travelled by P while it meets Q = d + 11

 Distance travelled by Q while it meets P = d – 11

 Distance travelled by Q while it meets R = d + 9

 Distance travelled by R while it meets Q = d – 9

 Here the ratio of speeds of P & Q => SP : SQ = d + 11 : d – 11

 The ratio of speeds of Q & R => SQ : SR = d + 9 : d – 9

 But given Ratio of speeds of P & R => P : R = 3 : 2

 SP/SR = SP/SQ x SQ/SR = (d+11)(d+9) / (d−11)(d−9)

 => (d+11)(d+9) / (d−11)(d−9) = 3/2

 =>  d = 1, 99

 => d = 99 satisfies.

 Therefore, Distance between A and B = 99

 

42)Running 3/4th of his usual rate, a man is 15min late. Find his usual time in hours  ?

 

A) 2/3 hrs            B) 3/4 hrs

C) 1/3 hrs            D) 1/4 hrs

 Answer & ExplanationAnswer: B) 3/4 hrs

 

Explanation:

Walking at 3/4th of usual rate implies that time taken would be 4/3th of the usual time. In other words, the time taken is 1/3rd more than his usual time

 so 1/3rd of the usual time = 15min

or usual time = 3 x 15 = 45min = 45/60 hrs = 3/4 hrs.

 

43)In what time a 360 m. long train moving at the speed of 44 km/hr will cross a 140 m. long bridge ?

 

A) 36 sec             B) 39 sec

C) 41 sec              D) 43 sec

 Answer & ExplanationAnswer: C) 41 sec

 

Explanation:

Speed = 44 kmph x 5/18 = 110/9 m/s

 We know that, Time = distance/speed

 Time = (360 + 140) / (110/9)

 = 500 x 9/110 = 41 sec.

 

44)Two trains start from same place at same time at right angles to each other. Their speeds are 36km/hr and 48km/hr respectively. After 30 seconds the distance between them will be ?

 

A) 900 mts          B) 300 mts

C) 250 mts          D) 500 mts

 Answer & ExplanationAnswer: D) 500 mts

 

Explanation:

Using pythagarous theorem,

distance travelled by first train = 36x5 / 18x30 = 300m

distance travelled by second train = 48x5 / 18x30 = 400m

so distance between them =√( 90000 + 160000) = √250000 = 500mts.

 

45)Two stations A and B are 200 km apart on a straight track. One train starts from A at 7 a.m. and travels towards B at 20 kmph. Another train starts from B at 8 a.m. and travels towards A at a speed of 25 kmph. At what time will they meet?

 

A) 12 a.m.           B) 1 p.m.

C) 11 a.m.           D) 12 p.m.

 Answer & ExplanationAnswer: D) 12 p.m.

 

Explanation:

Assume both trains meet after 'p' hours after 7 a.m.

Distance covered by train starting from A in 'p' hours = 20p km

Distance covered by train starting from B in (p-1) hours = 25(p-1)

Total distance = 200

=> 20x + 25(x-1) = 200

=> 45x = 225

=> p= 5

Means, they meet after 5 hours after 7 am, ie, they meet at 12 p.m.

 

46)If Hema walks at 12 km/hr instead of 8 km/hr, she would have walked 20 km more. The actual distance travelled by Hema is ?

 

A) 40 kms            B) 30 kms

C) 46 kms            D) 32 kms

 Answer & ExplanationAnswer: A) 40 kms

 

Explanation:

Let the actual distance travelled be x km.

Then x/8=(x+20)/12

=> 12x = 8x + 160

=> 4x = 160

=> x = 40 km.

 

47)In a race of 800m Kaushik gives Piyush a start of 200m and then loses the race by 20 seconds. What is the speed of Piyush and Kaushik respectively ? If the ratio of respective speeds be 3:2.

 

 Answer

Let the speed of Kaushik be Sk and speed of Piyush be Sp and let the time taken by Piyush be t second then,

Sk/Sp = (800 / t+20)/(600/t) = 2/3(since given ratio)

 t = 20 s

 Speed of Piyush = Sp = 600/20 = 30 m/s

 and Speed of Kaushik = 800/40 = 20 m/s

 

48)Buses start from a bus terminal with a speed of 20 km/hr at intervals of 10 minutes. What is the speed of a man coming from the opposite direction towards the bus terminal if he meets the buses at intervals of 8 minutes?

 

A) 5 kmph            B) 6 kmph

C) 7.5 kmph        D) 8 kmph

 Answer & ExplanationAnswer: A) 5 kmph

 

Explanation:

Let p be the speed of man in kmph

 According to the given data in the question,

 Distance travelled by bus in 10 min with 20 kmph == Distance travelled by man in 8 min with (20 + p) kmph in opposite direction

 => 20 x 10/60 = 8/60 (20 + p)

 => 200 = 160 + 8p

 => p = 40/8 = 5 kmph.

 

49)Kamal consistently runs 240 meters a day and on Saturday he runs for 400 meters. How many kilometers will he have to run in four weeks ?

 

A) 5.75 kms         B) 7.36 kms

C) 8.2 kms           D) 6.98 kms

 Answer & ExplanationAnswer: B) 7.36 kms

 

Explanation:

Total running distance in four weeks = (24 x 240) + (4 x 400)

 = 5760 + 1600

 = 7360 meters

 = 7360/1000

 => 7.36 kms

 

50)Two trains 85 m and 75 m long are running in same direction with speeds of 62 km/hr and 44 km/hr respectively. In what time will the first train cross the second train ?

 

A) 22 sec             B) 32 sec

C) 42 sec              D) 52 sec

 Answer & ExplanationAnswer: B) 32 sec

 

Explanation:

Given that,

 1st train speed = 62 km/hr

 2nd train speed  = 44 km/hr

 Hence the relative speed of two trains is : 62-44 = 18 km/hr = 18×(5/18) m/s = 5 m/s.

 There fore, the first train crosses the second train i.e (85+75)mts of distance with a speed of 5m/s in,

 time = distance/speed = (85+75) / 5 = 32 sec.