The area of a rectangle is 252 cm2 and its length and breadth are in the ratio of 9 : 7 respectively. What is its perimeter ?

Answer: Option A

Let the length and breadth of the rectangle be (9x) cm and (7x) cm respectively.
Then,
$$\begin{array}{rl}& 9x\times 7x=252\\ & \Rightarrow 63x^2=252\\ & \Rightarrow x^2=4\\ & \Rightarrow x=2\end{array}$$
So, length = 18 cm, breadth = 14 cm
∴ Perimeter :
= 2(18 + 14) cm
= 64 cm