Question

The length of a rectangle is increased by 60%. By what percentage would the width have to be decreased to maintain the same area?

• A. $37\frac{1}{2}\%$
• B. 60%
• C. 75%
• D. None

Answer 1

The correct option is A $37\frac{1}{2}\%$

Let length = l and breadth = b.

Let the required decrease in breadth be x%

$Then,\frac{160}{100}l\times \frac{(100-x)}{100}\times b=lb$

$\Rightarrow 160(100-x)=100\times 100$

$or100-x=\frac{10000}{160}=\frac{125}{2}$

$\Rightarrow x=(100-\frac{125}{2})=37\frac{1}{2}$