If the sides of an equilateral triangle are increased by 20%, 30% and 50% respectively to form a new triangle the increase in the perimeter of the equilateral triangle is

Answer: Option B

Perimeter of equilateral triangle = 100 + 100 + 100 = 300
Perimeter of New triangle
= 120 + 150 + 130
= 400
% increase $$=\frac{100}{300}\times 100=33\frac{1}{3}\%$$