The difference between the outer and inner curved surfa

SOLUTION

We have to find the inner and the outer radius of a hollow cylinder whose height(h) = 14 cm

So,

Outer curved surface area - Inner curved surface area = 88

$\Rightarrow$2$\pi$ (R-r) = 88

$\Rightarrow$ (R-r) = $\frac{88}{2\times \frac{22}{7}\times 14}$

$\Rightarrow$ (R-r) = 1   --------(i)

Also we have,

Volume of outer part - Volume of inner part = 176

$\Rightarrow$ $\pi$ h \(R^2 - r^2) = 176 

$\Rightarrow$ $\pi$ h  (R-r) (R+r) = 176 

$\Rightarrow$ $\pi$ h (R+r) = 176

$\Rightarrow$ $\frac{22}{7}$ × 14 (R+r) = 176

$\Rightarrow$ (R+r)  = 4 -------(ii)

From eq.(i) and (ii)

R = $\frac{5}{2}$

r = $\frac{3}{2}$