Question

An iron tank with an open top is cylindrical in shape. It has a height of $10m$ and radius $7m.$ It gets corroded at a rate of $3m^2/day.$ The number of days in which it gets completely corroded is [Take $\pi =\frac{22}{7}$]

• A. 192
• B. 202
• C. 198
• D. 208

Answer 1

The correct option is C

198

Total surface area of the tank $=$ Curved Surface area $+$ Base area
$=2\pi rh+\pi r^2$
$=2\times \frac{22}{7}\times 7\times 10+\frac{22}{7}\times 7^2$
$=594m^2$
Total number of days to get completely corroded $=\frac{\text{Total surface srea of the tank}}{\text{Area corroded per day}}$
$=\frac{594}{3}=198$