Question

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

• A. 25 %
• B. 33 1/3 %
• C. 75 %
• D. 100 %

Answer 1

Answer:

B. 33 1/3 %

Let the side of equilateral triangle be x units.

Perimeter = 3x units.

After increase,

Perimeter = 1.2x + 1.3x +1.5x

= 4x units

Increase = 4 x – 3x = x units

% Increase $=\frac{x}{3x}\times{100}=\frac{100}{3}=33\frac{1}{3}$%