Question

Suppose c and dare inversely proportional. If c=9 when d=8, find the value of d when c=6.

Answer 1

12

Explanation:

The multiple of c and d have to be the same no matter what numbers they are.

9 · 8 = 72, so d · 6 must be 72 also.

72 ÷ 6 = 12.

d = 12

Answer 2

Well, I believe you can set up a proportion for this. So:
d/c = d/c or 8/9 = x/6
*cross multiply*
9x = 48
*divide both sides by 9 to get x by itself*
x = 5 1/3