21. 

A takes twice as much time as B or thrice as much time as C to finish a piece of work. Working together, they can finish the work in 2 days. B can do the work alone in:

A. 4 days
B.

6 दिन

C.

8 दिन

D.

12 दिन


22. 

A and B can complete a work in 15 days and 10 days respectively. They started doing the work together but after 2 days B had to leave and A alone completed the remaining work. The whole work was completed in :

A. 8 days
B.

10 दिन

C.

12 दिन

D.

15 दिन


23. 

A and B can do a piece of work in 30 days, while B and C can do the same work in 24 days and C and A in 20 days. They all work together for 10 days when B and C leave. How many days more will A take to finish the work?

A. 18 days
B.

24 दिन

C.

30 दिन

D.

36 दिन


24. 

A works twice as fast as B. If B can complete a work in 12 days independently, the number of days in which A and B can together finish the work in :

A. 4 days
B.

6 दिन

C.

8 दिन

D.

18 दिन


25. 

Twenty women can do a work in sixteen days. Sixteen men can complete the same work in fifteen days. What is the ratio between the capacity of a man and a woman?

A. 3 : 4
B.

4: 3

C.

5: 3

D.

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