#100 Late for the gate
This deceptively tricky everyday problem set in an airport was first posed by the US mathematician Terence Tao in 2008.
You are in a bit of a rush to catch your plane, which is leaving from a remote gate in the terminal. Some stretches of the terminal have moving walkways, or travelators, and others are carpeted. You always walk at the same speed, but travelators obviously boost this.
You look down and spot that your shoelaces have come undone. This won’t slow you down, but it is annoying, so you decide to stop to tie…
