Time and Distance problems
- 1. 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?
Options- A. 50 sec
- B. 52 sec
- C. 54 sec
- D. 56 sec Discuss
Correct Answer: 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
- 2. 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
Options- A. 4 hours
- B. 4 hours 30 minutes
- C. 4 hours 45 minutes
- D. 5 hours Discuss
Correct Answer: 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
- 3. A man walking at the rate of 5 km/hr crosses a bridge in 15 minutes. The length of the bridge (in metres) is
Options- A. 600
- B. 750
- C. 1000
- D. 1250 Discuss
Correct Answer: 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.
- 4. 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
Options- A. 35.55 km/hr
- B. 36 km/hr
- C. 71.11 km/hr
- D. 71 km/hr Discuss
Correct Answer: 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.
- 5. 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?
Options- A. 10 a.m
- B. 10.30 a.m
- C. 11 a.m
- D. 11.30 a.m Discuss
Correct Answer: 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.
- 6. Akash leaves mumbai at 6 am and reaches Bangalore at 10 am . Prakash leaves Bangalore at 8 am and reaches Mumbai at 11:30 am. At what time do they cross each other?
Options- A. 10 am
- B. 8:32 am
- C. 8:56 am
- D. 9:20 am Discuss
Correct Answer: 8:56 am
Explanation:
Time taken by Akash = 4 h
Time taken by Prakash = 3.5 h
For your convenience take the product of times taken by both as a distance.
Then the distance = 14km
Since, Akash covers half of the distance in 2 hours(i.e at 8 am)
Now, the rest half (i.e 7 km) will be coverd by both prakash and akash
Time taken by them = 7/7.5 = 56 min
Thus , they will cross each other at 8 : 56am.
- 7. In a one km race A gives B a start of 100m and in a one km race B gives a start of 80 m to C. In a 1 km race who will win and by how much distance from the worst performer between two losers?
Options- A. 182 m
- B. 152 m
- C. 172 m
- D. 162 m Discuss
Correct Answer: 172 m
Explanation:
Ratio of speeds of A:B = 1000:900 = 100:90 Ratio of speeds of B:C = 1000:920 = 100:92 Therefore, when A moves 1000m, B moves 900 m and when B moves 900m, C moves 828m Since, C moves 8 % less than B at the same time. Thus, C is the worst performer and A will win by him by 172 m
- 8. 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:
Options- A. 120m
- B. 150m
- C. 125m
- D. None of these Discuss
Correct Answer: 150m
Explanation:
Let the length of the train e x meter, and let the speed of train be y km/h, then
--------(1) and
---------(2)
From eq (1) and (2), we get
y = 12 km/h
Therefore, => x= 150 m
- 9. The distance of the college and home of Rajeev is 80km. One day he was late by 1 hour than the normal time to leave for the college, so he increased his speed by 4km/h and thus he reached to college at the normal time. What is the changed (or increased) speed of Rajeev?
Options- A. 28 km/h
- B. 30 km/h
- C. 40 km/h
- D. 20 km/h Discuss
Correct Answer: 20 km/h
Explanation:
Let the normal speed be x km/h, then
x (x + 20) - 16 (x + 20) = 0
(x + 20 ) (x - 16) =0
x = 16 km/h
Therefore (x + 4) = 20 km/h
Therefore increased speed = 20 km/h
- 10. A train with 120 wagons crosses Arun who is going in the same direction, in 36 seconds. It travels for half an hour from the time it starts overtaking the Arun ( he is riding on the horse) before it starts overtaking the Sriram( who is also riding on his horse) coming from the opposite direction in 24 seconds. In how much time (in seconds) after the train has crossed the Sriram do the Arun meets to Sriram?
Options- A. 3560 sec
- B. 3600 sec
- C. 3576 sec
- D. can't be determined Discuss
Correct Answer: 3576 sec
Explanation:
Let the length of the train be L metres and speeds of the train Arun and Sriram be R, A and S respectively, then
---------- (i)
and ---------(ii)
From eq.(i) and (ii)
3(R - A ) = 2 (R + K)
R = 3A + 2K
In 30 minutes (i.e 1800 seconds), the train covers 1800R (distance) but the Arun also covers 1800 A (distance) in the same time. Therefore distance between Arun and Sriram, when the train has just crossed Sriram
= 1800 ( R - A) - 24 ( A + K)
Time required =
= (3600 - 24) = 3576 s
More in Aptitude:
Programming
Copyright ©CuriousTab. All rights reserved.