AHSME 1951 Problem 39

A stone is dropped into a well and the report of the stone striking the bottom is heard $7.7$ seconds after it is dropped. Assume that the stone falls $16t^2$ feet in t seconds and that the velocity of sound is $1120$ feet per second. The depth of the well is: $\textbf{(A)}\ 784\text{ ft.} \textbf{(B)}\ 342\text{ ft.} \textbf{(C)}\ 1568\text{ ft.} \textbf{(D)}\ 156.8\text{ ft.} \textbf{(E)}\ \text{none of these}$