Question

A cylindrical container with internal radius of its base $10$ cm, contains water up to a height of $7$ cm. Find the area of the wet surface of the cylinder.

• A. $774.29$ $c{m}^2$
• B. $784.29$ $c{m}^2$
• C. $754.29$ $c{m}^2$
• D. $724.29$ $c{m}^2$

Answer 1

Answer: (C)

$754.29$ $c{m}^2$

Given, a cylindrical container with internal radius $10$ cm and water filled up to height $7$ cm.
Wet surface area of cylinder $=$ curved surface area of cylinder up to $7$ cm $+$ area of base of cylinder

$=2\pi rh+\pi r^2$

$=\pi r(2h+r)$

$=\frac{22}{7}\times 10\times (14+10)=\frac{22}{7}\times 10\times 24=754.29{cm}^2$