Question

$X$ is twice as good as a workman as $Y$. $X$ finished a piece of work in 3 hours less than $Y$. In how many hours could they have finished that piece of work together?

• A. 3
• B. 2
• C. 4
• D. 5

Answer 1

The correct option is B 2

$X$ finished a work in 3 hours less than $Y$. $X$ is twice as good as a workman as $Y$. Therefore, $Y$ finished the same work in 6 hours.
$\therefore (X+Y)$'s one hour's work $=\frac{1}{3}+\frac{1}{6}=\frac{3}{6}=\frac{1}{2}$
$\therefore X$ and $Y$ together can finish the whole work in 2 hours.