Question

If the ratio of the sum and the difference of two numbers is 7 : 2, then the ratio of these two numbers is

• A. 7 : 5
• B. 9 : 5
• C. 9 : 7
• D. 7 : 4

Answer 1

Answer: (B)

9 : 5

Let $x$ and $y$ be the numbers then

$\frac{x+y}{x-y}=\frac{7}{2}$(given)

$\Rightarrow 2x+2y=7x-7y$

$\Rightarrow 2x-7x=-7y-2y$

$\Rightarrow -5x==9y$

$\Rightarrow \frac{x}{y}=\frac{9}{5}$

or $x:y=9:5$