Question

A alone can finish a piece of work in 12 days and B alone can do it in 15 days if both of them work at it together how much time will it take to finish it

Answer 1

Answer:

6.6 days

This is very easy just take the reciprocal of work as work done in 1 days

Answer 2

Answer:

Both can finish the work in $6 \frac{2}{3}$

days

Step-by-step explanation:

Time taken by A to finish the work = 12 days

Time taken by B to finish the work = 15 days

Work done by A in 1 day = ½

Work done by B in 1 day = 1/15

Work done by (A+B) in 1 day = $( \frac{1}{12} + \frac{1}{15} ) = \frac{9}{30} = \frac{3}{20}$

Time taken by (A + B) to finish the work $\frac{20}{3}$days, i.e., $6 \frac{2}{3}$days.

Hence, both can finish the work in

$6 \frac{2}{3}$days.