Henry Ernest Dudeney/Puzzles and Curious Problems/62 - At Right Angles/Solution/Proof 2

by : $62$

 * At Right Angles

Proof
From Time when Hour Hand and Minute Hand at Right Angle, the times when this is between $5$ and $6$ are:


 * $05:10:55$

and:
 * $05:43:38$

The first of these is the earlier of those two times.