Time & work, pipes aptitude

Question 1

A can finish a job in 12 days and B in 18 days. Working together, how long will they take?

Accepted Answer

7.2 days

Answer

15 days

Answer

6 days

Answer

7.5 days

Question 2

A and B together can finish a task in 10 days, and A alone can do it in 15 days. How long would B alone take?

Accepted Answer

30 days

Answer

25 days

Answer

20 days

Answer

5 days

Question 3

A can do a piece of work in 20 days and B in 30 days. They work together for 6 days, then A leaves. In how many more days will B finish the work?

Accepted Answer

15 days

Answer

12 days

Answer

18 days

Answer

10 days

Question 4

12 workers can build a wall in 18 days. How many days will 9 workers take to build the same wall?

Accepted Answer

24 days

Answer

13.5 days

Answer

20 days

Answer

27 days

Question 5

Pipes A and B can fill a tank in 6 hours and 8 hours respectively, while pipe C can empty it in 12 hours. If all three are opened together, how long will the empty tank take to fill?

Accepted Answer

4 h 48 min

Answer

4 h 30 min

Answer

3 h 26 min

Answer

5 h 20 min

Question 6

A pipe can fill a tank in 10 hours, but because of a leak it takes 12 hours. How long would the leak take to empty a full tank?

Accepted Answer

60 hours

Answer

22 hours

Answer

2 hours

Answer

120 hours

Question 7

A is twice as efficient as B, and together they finish a job in 14 days. How long would A alone take?

Accepted Answer

21 days

Answer

28 days

Answer

42 days

Answer

18 days

Question 8

6 men or 10 women can complete a job in 30 days. How long will 6 men and 5 women together take?

Accepted Answer

20 days

Answer

15 days

Answer

24 days

Answer

18 days