If x varies directly as y3 and x = 2 when y = 1, find…

If x varies directly as y³ and x = 2 when y = 1, find x when y = 5

Correct Answer: Option D

Explanation

x (alpha) y³
x = ky³
k = (frac {x}{y^3})
when x = 2, y = 1
k = 2
Thus x = 2y³ – equation of variation
= 2(5)³
= 250