Answer:
B
Step-by-step explanation:
Given y varies directly as x, then the equation relating them is
y = kx ← k is the constant of variation
To find k use the condition when x = 20, y = 12, then
12 = 20k ( divide both sides by 20 )
k = [tex]\frac{12}{20}[/tex] = [tex]\frac{3}{5}[/tex]
y = [tex]\frac{3}{5}[/tex] x ← equation of variation
When x = 15, then
y = [tex]\frac{3}{5}[/tex] × 15 = 9
