Question

The sum of three numbers is 107. The second number is 7 less than the first. The third number is 3 times the second. What are the numbers?

Answer 1

27, 20, 60

Explanation:

We use the equation

(x) + (x - 7) + (3 * (x - 7)) = 107

= x + x - 7 + 3 * (x - 7) = 107

= 2x - 7 + 3(x - 7) = 107

Add 7 on both sides

= 2x + 3(x - 7) = 114

Expand the 3

= 2x + 3x - 21 = 114

= 5x - 21 = 114

Add 21 on both sides

= 5x = 135

Divide 5 on both sides

= 5x/5 = 135/5

= x = 27

Plug the functions in

(27) + (27 - 7) + (3 * (27-7)) = 107

You would get

27 + 20 + 60 = 107, therefore the numbers are 27, 20, 60