The sum of radius of circles is 119 cm and the difference between their area is 17204 sq. cm. What is the radius (in cm) of the larger circle?
Answer & explanation
Correct answer: option 4
Sum of radius = r1 + r2 = 119 (r1 > r2)
Difference in area = π r12 - π r22
17204 = π (r1 - r2) (r1 + r2)
17204 = \(\frac{22}{7}\) × 119 × (r1 - r2)
⇒ (r1 - r2) = 46
⇒ (r1 + r2) = 119
Adding both, we get
⇒ 2 r1 = 165
⇒ r1 = 82.5