Question

Diameter of a football is $28cm$. It is made up of small hexagons each of surface area $112{cm}^2$. Find the number of small hexagons used in football.

• A. $21$
• B. $27$
• C. $23$
• D. $22$

Answer 1

The correct option is D $22$

We know that, the surface area of sphere $=4\pi r^2$ .....(where, $r=$ radius).

Here, radius $=\frac{\text{Diameter}}{2}=\frac{28}{2}=14cm$.

Given, surface area of each hexagon is $112c{m}^2$.

Then, Number of hexagons $=\frac{\text{Total surface area of sphere}}{\text{Surface area of one hexagon}}$

$=\frac{4\pi (14{)}^2}{112}$

$=\frac{4\times \frac{22}{7}\times 14\times 14}{112}$

$=\frac{17248}{7\times 112}=22$.

$\therefore$ Number of hexagons $=22$.

Hence, option $D$ is correct.