Megan and Hana raced their remote control cars for $100 \mathrm{~m}$.

The two cars started at the same time.

The average speed of Megan's car was $\frac{5}{4} \mathrm{~m} / \mathrm{s}$.

Hana's car finished 5 seconds before Megan's car.

What was the average speed of Hana's car?
(A) $\frac{4}{5} \mathrm{~m} / \mathrm{s}$
(B) $\frac{5}{2} \mathrm{~m} / \mathrm{s}$
(C) $\frac{4}{3} \mathrm{~m} / \mathrm{s}$
(D) $\frac{6}{5} \mathrm{~m} / \mathrm{s}$
(E) $\frac{3}{2} \mathrm{~m} / \mathrm{s}$
Megan's car travels $100 \mathrm{~m}$ at $\frac{5}{4} \mathrm{~m} / \mathrm{s}$, and so takes $\frac{100 \mathrm{~m}}{5 / 4 \mathrm{~m} / \mathrm{s}}=\frac{400}{5} \mathrm{~s}=80 \mathrm{~s}$.

Hana's car completes the $100 \mathrm{~m}$ in $5 \mathrm{~s}$ fewer, and so takes $75 \mathrm{~s}$.

Thus, the average speed of Hana's car was $\frac{100 \mathrm{~m}}{75 \mathrm{~s}}=\frac{100}{75} \mathrm{~m} / \mathrm{s}=\frac{4}{3} \mathrm{~m} / \mathrm{s}$.

ANSWER: (C)