Aptitude :: Time and Work

Practice :: Time and Work - General Questions
Time and Work - General Questions

Page Title 6. A and B together can do a piece of work in 30 days. They worked together for 20 days and then B left. After another 20 days, A completed the remaining work. In how many days A alone can complete the work?
37
55
60
48
Answer: option C

(A + B)'s 20 day's work = (1/30 x 20) = 2/3

Remaining work = (1 - 2/3) = 1/3

now, 1/3 work is done by A in 20 days.

∵ Therefore, the whole work will be done by A in (20 x 3) = 60 days.



7. 10 women can complete a piece of work in 7 days and 10 children take 14 days to complete the work. In how many days will it take 5 women and 10 children to complete the work?
3
5
15
7
Answer: option D

1 woman's 1 day's work = 1/70

1 child's 1 day's work = 1/140

(5 women + 10 children)'s day's work = (5/10 + 10/140) = (1/14 + 1/14) = 1/7

∵ 5 women and 10 children will complete the work in 7 days.



8. On a tour a man travels first 160 km at 64 km/h and the next 160 km at 80 km/h. The average speed for the first 320 km of the tour is:
65 km/hr
71.11 km/hr
42 km/hr
55 km/hr
Answer: option B

Total time taken = (160/64 + 160/80) hrs. = 9/2 hrs.

∵ Average speed = (320 x 2/9) km/hr. = 71.11 km/hr



9. A can do a piece of work in 18 days and B can do the same work in 15 days. B worked for 10 days and left the work. In how many days can A alone complete the remaining work?
6 days
9 days
5 days
7 days
Answer: option A

B's 10 day's work = (1/15 x 10) = 2/3

Remaining work = (1 - 2/3) = 1/3

now, 1/18 work is done by A in 1 day

∵ 1/3 work is done by A in (18 x 1/3) = 6 days



10. 4 men and 6 women can complete a piece of work in 8 days, while 3 men and 7 women can complete it in 10 days. In how many days will 10 women complete it?
26 days
56 days
40 days
24 days
Answer: option C

Let 1 man's 1 day's work = X and 1 woman's 1 day's work = Y.

Then, 4X + 6Y = 1/8 and 3X + 7Y = 1/10

Solving the two equations, we get: X = 11/400, Y = 1/400

1 woman's 1 day's work = 1/400

∵ 10 women's 1 day's work = (1/400 x 10) = 1/40

Hence, 10 women will complete the work in 40 days.




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