y varies directly as w2. When y = 8, w = 2. Find y when w = 3
A
18
B
12
C
9
D
6
Verified Correct Answer: A.
Step-by-Step Mathematical Solution
\(y \propto w^2\)
y = kw2
8 = k(2)2
8 = k(4)
k = 8/4
k = 2
Thus y = 2w2
When w = 3, y = 2(3)2
y = 2 x 9 = 18
Source: Myschool Past Questions Archive (Record #27008)