Subject: General Aptitude · Chapter: Area · Exam: · Marks: · Difficulty:
The length of a rectangle is halved, while its breadth is tripled. What is the percentage change in area?
(a)25\% increase
(b)50\% increase
(c)50\% decrease
(d)75\% decrease
Answer
Answer (as printed): B
Explanation
Let original length $=x$ and original breadth $=y$. Then, original area $=x y$. New length $=\frac{x}{2}$; New breadth $=3 y$; New area $=\left(\frac{x}{2} \times 3 y\right)=\frac{3}{2} x y$. ∴ Increase $\%=\left(\frac{1}{2} x y \times \frac{1}{x y} \times 100\right) \%=50 \%$.
Explanation as extracted from the printed page; notation may be imperfect.