Question

If w varies jointly as x and y when w = 12, x = 2, and y = 18, what is the value of y when w = 16 and x = 6?

8/9
13.5
8

Answer 1

The answer is eight

Answer 2

Joint variation means that w=kxy where k is constant.
Finding k:
12=k*2*18
12=36k
k=1/3

Now plug in second set of values
16= 1/3*6*y
16=2*y
y=8

Final answer: 8