Question

The variable y is directly proportional to the variable x. If y = 10 when x = 6, what is the value of y when x = 15?

Answer 1

Create a proportion:

x/y = 6/10

Plug in 15 for x and solve for y.

15/y = 6/10

Cross multiply.

150 = 6y

Divide both sides by 6.

y = 25