If 10 men or 20 women or 40 children can do a piece of work in 7 days, then 5 men, 5 women and 5 children together can do half of the work in 

A, B and C can do a work in 6, 12 and 24 days respectively. In what time will they finish the work while working together?

A and B can separately complete a piece of work in 20 days and 30 days respectively. They worked together for some time then B left the work. If A completed the rest of the work in 10 days, then B worked for how many days?

A contractor undertakes to finish a certain work in 124 days and employed 120 men. After 64 days, he found that he had already done 2/3 of the work. How many men can be discharged so that the work may finish in time ?

A contractor undertakes to make a road in 40 days and employs 25 men. After 24 days, he finds that only one- third of the road in made. How many extra men should he employ so that he is able to complete the work 4 days earlier?

If 12 men and 16 boys can do a piece of work in 5 days; 13 men and 24 boys can do it in 4 days, then the ratio of the daily work done by a man to that of a boy is 

A and B can do a work in 12 days, B and C in 15 days, C and A in 20 days. If A, B and C work together, they will complete the work in 

A and B can do a work in 18 and 24 days respectively. They worked together for 8 days and then A left. The remaining work was finished by B in