3 men or 15 boys can do a piece of work in 30 days. In how many days will 2 men and 5 boys do this work?

P can complete a work in 20 days while Q is 25% more effiecent than P. Q worked for 6 days and left, remaining work is completed by R in 15 days. Find in how many days R can complete the whole work alone?

A can do a certain work in 12 days. B is 60% more efficient than A. How many days does B alone take to do the same work?

The construction work is assign to the Group-I of 7 workers. They complete the task in 12 days. The another Group-II started the same task with same number of workers. They started the work and just after 5th day their 2 workers left the work. Now, in how many days this Group will complete the task ?

40 men can complete a work in 48 days. 56 men started for the same work for x days. After x days, 16 men increased, so, the remaining work is completed in $13\frac{1}{3}$ days. Find x?

18 women complete a work in 24 days and 24 men complete the same work in 15 days. 16 women worked for 3 days and then they left. 20 men worked for the next 2 days, and then they are joined by 16 women. In how many days will they finish the remaining work?

A is twice as good as a workman B and together they finish a piece of work in 18 days. In how many days will A alone finish the work?