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. अपर्याप्त डेटा