Question

Difference between circumference & diameter of circle is 28cm. find its radius

Answer 1

Diameter(d)=2r
circumference =2×22/7×r

Given that 2×22/7×r - d = 28

therefore
2 × 22/7 × r - 2r = 28
2 (22/7 × r - r) = 28
22/7 × r - r = 14
22r - 7r = 14 ×7
15r = 98
r = 98 / 15

r = 6.53 (approx)