Question

A can do a piece of work in $24$ days. If B is $60\%$ more efficient then the number of days required by B to do the twice as large as the earlier work is-

• A. $24$
• B. $36$
• C. $15$
• D. $30$

Answer 1

The correct option is D $30$

According to the question-

A can do a piece of work in $24$ days.

$\therefore$ work done by A in $1$ day $=\frac{1}{24}$

Given that, B is $60\%$ more efficient, i.e., B can do $60\%$ more work than work done by A in $1$ day-

Work done by B in $1$ day $=\frac{1}{24}+\frac{60}{100}\times 124=\frac{1}{15}$

$\therefore$ number of days required by B to do the same work $=15$days

$\therefore$ number of days required by B to do the twice as large as the earlier work $=2\times 15=30$ days