Question

A closed metallic cylindrical box is $1.5m$ high and it has a base whose diameter is $70cm.$ If the sheet of metal costs $Rs.70$ $per$ $sq.m$, find the cost of the material used in the box.

Answer 1

$h=1.5$ m $r=\frac{35}{100}=0.35$ m

TSA $=2\pi rh+2\pi r^2=2\pi r(r+h)$

$=2\times \frac{22}{7}\times 0.35\left(1.85\right)=4.07m^2$

Cost $=70\times 4.07=284.9$ Rs.