Question

Find the ratio of the total area of the grid shown below to the approximate area covered by the pizza if the side of smallest square is 1 cm and each such square is congruent?

• A.
  $6:5$
• B.
  $4:3$
• C.
  $5:3$
• D.
  $7:3$

Answer 1

The correct option is D

$7:3$
Side of the smallest square $=1cm$

⇒ Area of one such square $=1\times 1=1c{m}^2$

⇒ Total area of the square grid $=7\times 7=49c{m}^2$

Let us count the squares that are completely covered, half covered and so on. Also, these can be marked as shown below:

Now, we need to write the number of squares that are covered by the shape.

Therefore, the approximate area of the given shape
$=12\times \left(1\right)+0\times \frac{1}{2}+9\times \left(1\right)+8\times \left(0\right)$
$=12+0+9+0$
$=21c{m}^2$

Hence, the required ratio = $\frac{49}{21}$ = $\frac{7}{3}$
$7:3$