Question

Solve the problem as directed. If x and y vary directly, and x = 10 when y = 3, what will be the value of x when y = 9?

Answer 1

A simple ratio will probably work. 10=3
x=9?
Cross multiply. 3x= 90 This x=30

Answer 2

X will equal 30. If y equals 9, then that means it was multiplied 3 times, so you do the same with x. 10*3=30.