Question

$A$ can finish a work in $18$ days and $B$ can do the same work in half the time taken by $A$. What part of the same work they can finish in a day if they work together?

• A. $\frac{1}{6}$
• B. $\frac{1}{9}$
• C. $\frac{2}{5}$
• D. $\frac{2}{7}$

Answer 1

The correct option is A $\frac{1}{6}$

$A^{\prime }s$ $1$ day work $=\frac{1}{18}$

$B^{\prime }s$ $1$ day work $=\frac{1}{9}$ [because B take half time than A]

$(A+B{)}^{\prime }s$ one day work $=\frac{1}{18}+\frac{1}{9}$

$(A+B{)}^{\prime }s$ one day work $=\frac{1+2}{18}=\frac{3}{18}$

$(A+B{)}^{\prime }s$ one day work $=\frac{1}{6}$