Question

Suppose $B$ is $60\%$ more efficient than $A$. If $A$ can finish a job in $15$ days, how many days $B$ needs to finish the same job?

Answer 1

$B$ is $60\%$ more efficient than $A$

$A$ finishes a job in $15$ days

So, $A$'s one day work $=\frac{1}{15}$

$\therefore$ $B$'s one day work will be

$\frac{1}{15}+60\%\text{of}\frac{1}{15}$

$=\frac{1}{15}+60\times \frac{1}{15}\times \frac{1}{100}$

$=\frac{1}{15}+\frac{1}{25}$

$=\frac{8}{75}$

So, $B$ finishes the work in $\frac{75}{8}=9\frac{3}{8}$ days.

Hence, $B$ can do the same work in $9\frac{3}{8}$ days.