Henry Ernest Dudeney/Modern Puzzles/39 - The Two Trains/Solution

by : $39$

 * The Two Trains

Solution
The faster train went at $54 \tfrac 6 {11}$ miles per hour.

The slower train went at $27 \tfrac 3 {11}$ miles per hour.

Proof
Let $v_1$ feet per second denote the speed of the faster train.

Let $v_2$ feet per second denote the speed of the slower train.

We have:

The result follows on converting $80$ feet per second and $40$ feet per second into miles per hour.