Math Help - Average velocity

1. Average velocity

during the first 50 s of a rocket's flight, the rocket is propelled straight up, so that in t seconds its height s is s(t)=t^3/sqrt(10)ft.

a)how high does the rocket travel in 50 s?

b) what is the average velocity of the rocket during the first 50s?

c)what is the average velocity of the rocket during the first 125ft?

$s(t) = \dfrac{t^3}{\sqrt{10}}$
Find $\dfrac{s(50) - s(0)}{50 - 0}$.
Plug in 125 for s(t) into your equation and solve for t. Whatever this answer is (I'll call it x), then find $\dfrac{125 - s(0)}{x - 0}$.