Question

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

Answer 1

b has to be decreased by 37.5%

Answer 2

$\huge\mathfrak{Answer}$

Let the length 100 metre and breadth be 100m, then

New length = 160m, new breadth = x,

$\sf \: Then \: \: \: \: \: \: \: \: 160 \times x = 100 \times 100 \\ \\ \sf \implies \: x = \frac{100 \times 100}{160} \implies \: x = \frac{125}{2}$

$\therefore \: \rm \: decrease \: in \: breadth \: = 100 - \frac{125}{2} \% \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \implies \sf \: 37 \: \frac{1}{2} \%$

So the answer is 37 and 1/2 %