Question

A cylindrical stool has a base of diameter 70 cm and height 25 cm find the cost of painting 50 such stools if the cost per m sq is rs 55.

Answer 1

Answer:

$Cost = Rs.3630$

Step-by-step explanation:

Given

$d = 70cm$ --- Diameter

$h = 25cm$ --- Height

$Cost = Rs.55$

$Cylinders = 50$

First, we calculate the surface area of 1 cylinder

This is calculated as:

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

The radius is calculated as:

$r =\frac{1}{2}d$

$r =\frac{1}{2}*70$

$r = 35$

The expression becomes:

$SA=2 * \frac{22}{7} * 35(35 + 25)$

$SA=2 * \frac{22}{7} * 35 * 60$

$SA=2 * 22 * 5 * 60$

$SA=13200cm^2$

Convert to $m^2$

$SA=\frac{13200m^2}{10000}$

$SA=1.32\ m^2$

The surface area of 50 of such is:

$Total = 50 * 1.32m^2$

$Total = 66m^2$

The cost is then calculated as:

$Cost = 66 * Rs.55$

$Cost = Rs.3630$