If x varies directly as y3 and x = 2 when y = 1, find x when y = 5
A
2
B
10
C
125
D
250
Verified Correct Answer: D.
Step-by-Step Mathematical Solution
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
Source: Myschool Past Questions Archive (Record #32063)