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If the radius of a circle be increasing ...

If the radius of a circle be increasing at a uniform rate of `2 cm//s`. The area of increasing of area of circle, at the instant when the radius is 20 cm, is

A

`70 pi cm^2//s`

B

`70 cm^2//s`

C

`80 pi cm^2//s`

D

`80 cm^2//s`

Text Solution

Verified by Experts

The correct Answer is:
C
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