** Question No : 15**

A does half as much work as B in three-fourth of the time. If together they take 18 days to complete the work, how much time shall B take to do it

25 days

26 days

28 days

30 days

** Question No : 16**

To complete a work A and B takes 8 days, B and C takes 12 days, A,B and C takes 6 days. How much time A and C will take

12 days

8 days

18 days

24 days

** Question No : 17**

A is thrice as good a workman as B and takes 10 days less to do a piece of work than B takes. B alone can do the whole work in

15 days

10 days

8 days

6 days

** Question No : 18**

A can do a piece of work in 15 days and B alone can do it in 10 days. B works at it for 5 days and then leaves. A alone can finish the remaining work in

5 days

6.5 days

7.5 days

8 days

** Question No : 19**

A can do a piece of work in 4 hours . A and C together can do it in just 2 hours, while B and C together need 3 hours to finish the same work. In how many hours B can complete the work ?

12 hours

15 hours

17 hours

20 hours

** Question No : 20**

A completes 80% of a work in 20 days. Then B also joins and A and B together finish the remaining work in 3 days. How long does it need for B if he alone completes the work?

$34\frac{1}{2}$

$35\frac{1}{2}$

$36\frac{1}{2}$

$37\frac{1}{2}$

** Question No : 21**

A alone can do a piece of work in 6 days and B alone in 8 days. A and B undertook to do it for Rs. 3200. With the help of C, they completed the work in 3 days. How much is to be paid to C

Rs. 200

Rs. 400

Rs. 600

Rs. 800