Question

The variable Z is directly proportional to X, and inversely proportional to Y. When X is 12 and Y is 18, Z has the value 2.

What is the value of Z when X = 19, and Y = 22

Answer 1

z = kx/y
2 = (k *12)/18
multiply both sides by 18
36 =  k * 12
divide both sides by 12
3 = k

z = 3x/y
z = (3 * 19)/22
z = 57/22