The variable Z is inversely proportional to X. When X is 3, Z has the value 6. What is the value of Z when X = 12

Question

 The variable Z is inversely proportional to X.  When X is 3, Z has the value 6.

What is the value of Z when X = 12

Answer 1

If Z is inversely proportional to X, Z = c/X, or XZ = c. 

When X is 3, Z is 6, so c = XZ = 3*6 = 18

Then, when X = 12, Z = c/X = 18/12 = 3/2