If the difference between the circumference and diameter of a circle is 60 cm , then the radious of the circle is-
A
7 cm
B
9 cm
C
10 cm
D
14 cm
Correct Answer: 14 cm
এখানে, 2π - 2r =60 ⇒ 2r (π -1) = 60 ⇒r (227-1)=30⇒r ×157=30⇒r=30×715∴ r =14