To determine the first and last places based on the times, we look for the fastest time (first place) and the slowest time (last place).
The times are:
- 31.18 seconds
- 27.9 seconds
- 32.41 seconds
- 29.7 seconds
The fastest time is 27.9 seconds (first place) and the slowest time is 32.41 seconds (last place).
So, the correct response is: First place: 27.9 seconds; last place: 32.41 seconds.