Sunday Times Teaser

[x_word_fan]

My six mile journey into the city centre consisted of six one mile legs, each of which I had driven at a steady speed of a whole number of miles per hour. I did not exceed the 20 miles per hour speed limit on the first leg and my speed on each subsequent leg was less than that on the leg that preceded it.

I calculated that the average speed to the end of each leg had been a whole number of miles per hour.

How long did the journey take?

I can only find a solution starting with 24mph anyone got an answer that works?

Thanks

[Dinkypuzzled]

The journey took 24 min. 20, 18, 16, 14, 12 and 10 being the speed per min. The averages work out at 19, 18, 17, 16 and 15 mph. 15mph for 6 miles = 24 min.

[drawoh46]

Only lust seen this post. Looking back at my notes (which I rarely throw away!) I see my solution had speeds of 20, 12, 6, 5, 2, 1 for the six legs.
This gave cumulative average speeds of:
20 for leg 1
15 for legs 1-2
10 for legs 1-3
8 for legs 1-4
5 for legs 1-5
3 for legs 1-6
Thus giving 2 hours for the whole journey.