CMAT 2015 Solved Question Paper

(d) Let the each side of equilateral triangles be 100.
∴ Area of a triangle = $\frac{\sqrt{3}}{4}\cdot {\left(\mathrm{side}\right)}^2$
$$ = $\frac{\sqrt{3}}{4}\cdot {\left(100\right)}^2$ = $\frac{\sqrt{3}}{4}\times 10000$
$$ = $2500\sqrt{3}$ sq. units
New length of side when 60% increased = 100 + 60% of 100
$$ = 100 + $\frac{60}{100}$ x 100 = 160
∴ Area of a triangle = $\frac{\sqrt{3}}{4}\cdot {\left(160\right)}^2$ = $6400\sqrt{3}$ sq units
∴ Required percentage increase in the area
$$ = $\frac{6400\sqrt{3}-2500\sqrt{3}}{2500\sqrt{3}}\times 100$
$$ = $\frac{3900\sqrt{3}}{2500\sqrt{3}}\times 100$ = 156 %