Mensuration Practice Test 10

Let length and width be l and b respectively.
Area of rectangle = l × b
New area of a rectangle when length is increased by 60% and let breadth be decreased by x %
= $\frac{160\mathit{l}}{100}\times \left(\mathit{b}-\frac{\mathit{x}\mathit{b}}{100}\right)$ = lb
= $\frac{160}{100}\times \left(\frac{100-\mathit{x}}{100}\right)$ = 1
= 100 - x = $\frac{1000}{16}$
= $100-\frac{1000}{16}$ = x
= $\frac{600}{16}$ = x
= 37.5 % = x