Answer:
x = 24
Explanation:
Given that y varies directly with x then the equation relating them is
y = kx ← k is the constant of variation
To find k use the condition y = 10 when x = 8, thus
k =
=
=

y =
x = 1.25x ← equation of variation
When y = 30
30 = 1.25x ( divide both sides by 1.25 )
x = 24