Question

Suppose y varies directly with x, and y = 15 when x = 3. What is y when x = 12?

Answer 1

y = 60 when x = 12

Explanation:

Direct variation is

y = kx

15 = k3

Divide by 3

15/3 = k

5 =k

y = 5x

Let x = 12

y = 5*12

y = 60