the difference between outside and inside surface of a cylindrical metalic pipe 14 cm long is 44 cm2. if the pipe is made of 99 cu. cm of metals. find the outer and inner radii of the pipe. plz rply fast.

Let r and R be the inner and outer radius of the cylindrical metallic pipe respectively.

Height of the metallic pipe, h = 14 cm

Curved surface area of the outer cylinder – Curved surface area of the inner cylinder = 44 cm2  (Given)

∴ 2Rh – 2rh = 44 cm2

⇒ 2 (R – r) × 14 cm = 44 cm2

Volume of the metal in the pipe = 99 cm3      (Given)

R2hr2h = 99 cm3

(R2r2) × 14 cm = 99 cm3

Adding (1) and (2), we get

From (2), we have

This, the inner and outer radius of the pipe are 2 cm and respectively.

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