Question

A B and C can do a piece of work in 10 days 12 days and 15 days respectively how long will they take to finish it if they work together

Answer 1

your answer..........................

Answer 2

A' s 1 day work = 1/10
Bs 1day work = 1/12
Cs 1 day work = 1/15
in 1 day they together does = 1/10 + 1/12 +1/15
10×12+12×15+15×10
=_____________________
10×12×15
=450/1800
=1/4 hence they can do the work in 4 days