Question

The length of a rectangle is increased by $60\%$. By what percent would the width be decreased so as to maintain the same area?

• A. $37\frac{1}{2}\%$
• B. $60\%$
• C. $75\%$
• D. $Noneofthese$

Answer 1

Answer: (A)

$37\frac{1}{2}\%$

Let length of rectangle $=100$ m
breadth $=100$ m
Original Area $=100\times 100=10000m^2$
New length $=160$ m
Let new breadth $=x$
New Area $=160x$
Since area of rectangle remains same
$\therefore 10000=160x$
$\therefore x=\frac{125}{2}$
Decrease in breadth $=(100-\frac{125}{2})\%$
$=37.5\%$