AHSME 1973 Problem 34

A plane flew straight against a wind between two towns in 84 minutes and returned with that wind in 9 minutes less than it would take in still air. The number of minutes (2 answers) for the return trip was $\textbf{(A)}\ 54 \text{ or } 18 \textbf{(B)}\ 60 \text{ or } 15 \textbf{(C)}\ 63 \text{ or } 12 \textbf{(D)}\ 72 \text{ or } 36 \textbf{(E)}\ 75 \text{ or } 20$