Y varies jointly as x, z, and w. when x=2, z=1, and w=12, then y=72. find y when x=1, z=2, and w=3

ANSWER: 18

EXPLANATION:

y=kxzw

where k is a constant
Making k the subject of the formula, we have

k=y/xzw

Inputting the values

k= 72/(2)(1)(12)

k=72/24

k = 3

Solving for y when x=1,z=2 and w=3

We have

y=kxzw

y = (3)(1)(2)(3)

y = 18

25% increaseplus i think decrease i only know increase: ((