Reply To: Puzzles

8th October 2025 at 10:53 am #107441

Guest

#104162 Robot question answer.

>What was the constant MPH speed that Speed-E set?

Let the speed of Speed-E be v, the speed of the column be w and the duration of the outward and return journeys be t1 and t2 respectively.

We know:

t1 + t2 = 1

and that Speed-E catches Head-E when

v.t1 = 10 + w.t1

and that Speed-E returns to End-E when:

v.t2 = v.t1 – w

In this case w = 1 and the above simplify to:

v.t1 = 10 + t1

and

v.t2 = v.t1 – 1

Solving for t1 we get:

t1 = (sqrt(101)-9)/2

and v = 1/(sqrt(101)-10) approximately 20.499 mph.