Question

If a,bandc can individually complete a task in 8, 12 and 24 days respectively, then how long will it take for a to complete the task if she is assisted by b and c on every third day?

Answer 1

a can complete work in = 8
in one day a will complete work = 1/8
b can complete work in = 12
in one day b will complete work = 1/12
c can complete work in = 24
in one day c will complete work = 1/24

let they will complete work in x days
so, in one day they will complete work = 1/x
so,
1/8 + 1/12 +1/24 = 1/x
3+2+1/24 = 1/x
6/24 = 1/x
1/4 = 1/x
x=4 days
so in four days they will complete the work together.