Question

The area of a wall is 10m x 9m. If the size of one tile is 18cm x 20cm, then find the total number of tiles needed to tile the whole wall.

• A. 250
• B. 4
• C. 2500
• D. 400

Answer 1

The correct option is C 2500

$1m=100cm$ $\therefore 1m^2=1m\times 1m=100cm\times 100cm$
=$10,000c{m}^2$
$\therefore$The area of the wall = $10m\times 9m=90m^2=9,00,000c{m}^2$
The are of a tile = $18cm\times 20cm$
= $360c{m}^2$
$\therefore$ The number of tiles needed = The area of the wall $÷$ the area of a tile
$\Rightarrow 9,00,000c{m}^2÷360c{m}^2$
= $2500$ tiles