A and B alone can complete a piece of work in 4 days and 8 days, respectively. In how many days will the work be completed, if they both work on alternate days starting with A?
Five men and 2 boys can do as much work in 30 days as 7 men and 10 boys can do in 15 days. How many boys should join 40 men to do the same work in 4 days?