Question

The sum of two numbers is equal to $20$ and their difference is $2.5$. Find the ratio of the numbers

• A. $9:7$
• B. $7:9$
• C. $3:5$
• D. $2:7$

Answer 1

The correct option is A $9:7$

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

$x+y=\mathrm{20...}\left(1\right)$

$x-y=\mathrm{2.5...}\left(2\right)$

$\left(1\right)+\left(2\right)\Rightarrow 2x=22.5$

$\Rightarrow x=11.25$

$\Rightarrow y=8.75$

$\therefore x:y=11.25:8.75$

$\Rightarrow x:y=9:7$