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[Phys-l] A kinematics question

Am I crazy, or is this 1-d kinematics question overdefined?
"A runner runs around a 400-m track in 1 minute, 5 seconds. What was the
runner's average speed? The runner began the run from a standing start and
finished the run with a sprint at 20% more than the average speed. What
was the runner's average acceleration over the entire run?"

Using two different methods, I get two different answers for the
acceleration. I suppose that there are a few possibilities:
- I screwed up!
- the problem is overdefined
- the problem's statement is unclear (or unclear to me).

I asked the author of the problem and got an interesting response that
describes a situation different from the one that I visualize when I read
it. Even at that, I'm ot convinced of the explanation, but I'll keep the
response to myself for the minute.

So... what do you think?
I will require:
- a snarky response about how this would be easier if we used bivectors
- a response with 2.3 x 10^8 references
- a post about how this problem was much better in the good old days with
a cryptic PS.