Question

Two men undertake to do a piece of work for rs.400. One alone can do it in 6 days. The other in 8 days. With the help of a boy they finish it in 3 days. The boy's share is

Answer 1

here we can think 3rd one can do this alone in X day,

so 3/6+3/8+3/X=1,X=24

so the boy's share 400×24/(24+8+6)=4800/19