If the sum of the circumferences of two circles with radii R1 and R2 is equal to the circumference of a circle of radius R, then
(A) R1 +R2=R
(B) R1 +R2>R
(C) R1 +R2<R
(D) Nothing definite can be said about the relationamong R1, R2 and R.
(A) R1 + R2=R
Solution
Radius of first circle= R1
circumference of first circle =2πR1
Radius of second circle =R2
circumference of second circle =2πR2
Radius of third circle = R
circumference of third circle=2πR
According to question
2πR1 + 2πR2=2πR
2π(R1 + R2)=2πR
R1 + R2=R
Hence option A is correct.