X is twice as good a workman as Y and together they finish a piece of work in 18 days. In how many days will X alone finish the work?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 27 days
“Twice as good a workman” means X does twice as much work each day as Y. Taking their daily work as 2 units and 1 unit, the whole work can be counted in units.
Together they do \(2+1=3\) units a day for 18 days, so the whole work is \(3\times18=54\) units
X alone does 2 units a day, so he needs \(\displaystyle \frac{54}{2}=\) 27 days