If the side of a square is tripled, then the ratio of the area of the resulting square to that of original square is:

Correct option is A

Formula Used:

Area of a square = side × side
Ratio = $$\frac {\text{New Area}}{ \text{Original Area}}$$​​
Solution:
Side of the original square be 'a'
Area of the original square = $$a^2$$​​
If the side is tripled, the new side becomes 3a.
Area of the new square =$$(3a)^2 = 9a^2$$​​
Ratio of the area of the new square to the original square = $$\frac{9a^2}{a^2} = \frac{9}{1}$$​​