Question

The sum of two numbers is 8. If their sum is four times their difference, find the numbers.

• A. 5, 3
• B. 7, 4
• C. 9, 6
• D. 10, 7

Answer 1

The correct option is A 5, 3

Let the numbers be x and y.

Hence, x + y = 8 ......(1)

and

x + y = 4(x-y)

$\Rightarrow$ 3x - 5y = 0 ......(2)

On multiplying equation (1) by 5, we get

5x + 5y = 40 ......(3)

On adding equations (2) and (3), we get

8x = 40

$\Rightarrow$ x = 5

On substituting x = 5 in equation (1), we get

5 + y = 8

$\Rightarrow$ y = 3

$\therefore$ The numbers are 5 and 3.