Question

Y varies directly as the cube root of x. Y is 30 when x is 1, how do you find y when x is 27?

Answer 1

`Y=90` when `x=27`

Explanation:

We are told the Y varies directly as the cube root of x

Thus `Y=k root3 x` For some `k in QQ`

We are also told that `Y=30` when `x=1`

`:. 30 = k root3 1 -> k=30`

Hence: `Y = 30 root3 27` when `x=27`

`Y= 30 xx 3 = 90`