Question

For the same amount of work, an adult takes 6 hours less than a boy. if together they complete the worj in 13 hours 20 minutres, find how much time will the boy alone take to complete the work

Answer 1

let time taken by adult be A and by Boy be B

Thus according to question

A = B - 6 hrs
or
A = B - 6*60 min
A = B - 360 min           eqn 1


Also

A + B = 13 hr 20 min
          = 13*60 + 20
A + B = 800 min            Eqn 2

Solving Eqn 1 and Eqn 2
we get

B = 580 min
or
B = 9 hrs 40 min