SSC GD Practice MCQs : Time, Work & Distance
A. TIME & WORK
1. A can complete a work in 12 days and B in 18 days. In how many days can both complete the work together ?
Options: A) 7.2 days B) 6.5 days C) 7 days D) 8 days
Soln
A’s 1 day work: 1/12
B’s 1 day work: 1/18
Together work in 1 day: 1/12 + 1/18
LCM of 12 and 18 = 36
= 3 + 2/36 = 5/36
Total days required: 36/5 = 7.2
Ans: A) 7.2 days
2. A and B can do a work together in 15 days. A alone can do it in 25 days. In how many days can B alone do it ?
Options : A) 30 days B) 25 days C) 40 days D) 35 days
Soln
(A+B)’s 1 day work = 1/15
A’s 1 day work = 1/25
B’s 1 day work: 1/15 - 1/25
LCM = 75
= 5-3/75 = 2/75
Days taken by B: 75/2 = 37.5
Closest option = 40 days
Ans: C) 40 days
3. A can do a work in 10 days. He worked for 4 days and B finished the remaining work in 6 days. In how many days can B alone do the whole work ?
Options: A) 15 days B) 12 days C) 18 days D) 20 days
Soln
A’s 1 day work: 1/10
Work done by A in 4 days: 4×1/10 = 4/10
Remaining work: 1- 4/10 = 6/10 = 3/5
B completed 3/5 work in 6 days.
So, B’s 1 day work: 3/5 / 6 = 1/10
Therefore, B alone can complete the whole work in:10 days
Ans: 10 days (Please check the solution not match with the given option)
4. 48 men can complete a work in 12 days. In how many days will 12 men complete the same work ?
Options: A) 7 days B) 8 days C) 48 days D) 24 days
Soln
Men × Days = Constant
48×12 = 12 × x
Ans: C) 48 days
5. A can do a work in 20 days and B in 30 days. They worked together for 6 days. Find the fraction of work remaining.
Options: A) 3/5 B) 2/5 C) 1/2 D) 2/3
Soln
1 day work together: 1/20 + 1/30
LCM = 60
= 3+2/60 = 5/60 = 1/12
Work done in 6 days: 6 × 1/12 = 1/2
Remaining work: 1 - 1/2 = 1/2
Ans: C) 1/2
6. Two pipes can fill a tank in 10 hours and 15 hours. If both are opened together, in how many hours will the tank be full ?
Options: A) 6 hours B) 8 hours C) 7 hours D) 5 hours
Soln
Combined work: 1/10 + 1/15
LCM = 30
= 3+2/30 = 5/30 = 1/6
Total time = 6 hours
Ans: A) 6 hours
7. A pipe fills a tank in 6 hours and a leak empties it in 9 hours. If both are opened together, in how many hours will the tank fill ?
Options: A) 18 hours B) 36 hours C) 24 hours D) 12 hours
Soln
Net work: 1/6 - 1/9
LCM = 18
= 3-2/18 = 1/18
When the net work done in 1 hour is:
it means only 1/18 part of the tank is filled in 1 hour.
So, to fill the whole tank (1 full work):
Dividing by a fraction means multiplying by its reciprocal)
Ans: A) 18 hours
Trick
- If 1 hour work = 1/18
- Then full work = 18 hours
B. TIME, SPEED & DISTANCE
9. A car travels 240 km in 4 hours. Find its speed.
Options: A) 60 km/h B) 40 km/h C) 50 km/h D) 70 km/h
Soln
Speed = Distance / Time
Ans: A) 60 km/h
10. A train 150 m long is running at 54 km/h. In how many seconds will it cross a pole ?.
Options: A) 9 sec B) 10 sec C) 8 sec D) 12 sec
Soln
Convert speed: 54 × 5/18 = 15 m/s
Time: 150/15 = 10
Ans: B) 10 sec
11. A man covers a distance of 90 km in 3 hours. Find the distance covered in 5 hours at the same speed
Options: A) 140 km B) 150 km C) 160 km D) 130 km
Soln
Speed: 90/3 = 30
Distance in 5 hours: 30 × 5 = 150
Ans: B) 150 km
12. Two cars start from two places 360 km apart and move towards each other at 60 km/h and 80 km/h. In how many hours will they meet ?
Options: A) 2 hours B) 3 hours C) 2.5 hours D) 1.5 hours
Soln
Relative speed: 60 + 80 = 140
Time: 360/140 = 2.57
Approx = 2.5 hours
Ans: C) 2.5 hours
13. A train crosses a platform in 18 seconds and a man in 12 seconds. If the train is running at 72 km/h, find the length of the platform
Options: A) 360 m B) 400 m C) 432 m D) 480 m
Soln
Speed of train: 72 × 5/18 = 20 m/s
When the train crosses a man in 12 sec:
= 240 m
When the train crosses the platform in 18 sec:
Total distance = 20 × 18
Now,
Ans: 120 m
14. A bike covers 180 km in 3 hours and returns in 2 hours. Find the return speed.
Options: A) 90 km/h B) 70 km/h C) 60 km/h D) 80 km/h
Soln
Return speed: 180/2 = 90
Ans: A) 90 km/h
16. A man walks 6 km North and then 8 km East. How far is he from the starting point ?
Options: A) 10 km B) 12 km C) 14 km D) 15 km
Soln
Using Pythagoras Theorem: √a2 + b2 = c
√62 + 82 = √36 + 64 = √100 = 10
Ans: A) 10 km