If 9 boy working 15/2 hours a day can finish a work in 20 days, then how many days will be taken by 12 boy working 6 hours a day to finish the work, it being given than 3 boy of latter type work as much as 2 boy of he former type in the same.

28.125 days. Total Boy hours required= 9*15/2*20 = 1350 Later type boys available of former type = (12/3)*2 = 8 Days required= 1350/(8*6) = 28.125 days

If A men working A hours a day can do A units of a work in A days, then how many units of work can be completed by B men working B hours per day.

Six men do a piece of work in 10 days with an effort of 6 hours per day. How many extra men are required for doing the work of double strength in 4 days with an effort of 5 hours per day

If 6 men and 8 boys can do a piece of work in 10 days while 26 men and 48 boys can do the same in 2 days. What will be the time taken by 15 men and 20 boys in doing the same type of work?

Rahul and Maneesh working separately can do a piece of work in 9 days and 12 days respectively. If they work for a day alternately, Rahul beginning, in how many days, the work will be completed?