What will be the decreased percent of the area of the circle, if the radius is decreased by 50%?

** Option:**

**A.**25%

**B.**50%

**C.**75%

**D.**100%

**Answer: C . 75%**

** Justification:**

If the radius of the circle is = r, then the area A = Pi*r*r

If the radius is decreased by 50%, so the new radius is = r/2, so the area a = pi*r*r/2*2 = A/4

So, the difference (of percent) of the area is = ((A-A/4) / A) * 100% = 3/4*100% = 75%