Question

Raman alone can finish a piece of work in $15$ days and Suman alone can do it in $18$ days if both of them work it together. How much time will they take to finish it?

Answer 1

Raman can finish a work in $15$ days.

$\therefore$ Raman’s one day work= $\frac{1}{15}$

Suman can finish a work in $18$ days.

$\therefore$ Suman’s one day work=$\frac{1}{18}$

Work done by both in one day-

$\frac{1}{15}$ + $\frac{1}{18}$

$=\frac{6+5}{90}$

$=\frac{11}{90}$

thus raman and suman canfinish the work together in $\frac{1}{\frac{11}{90}}=\frac{90}{11}$ days