Cambridge Secondary (7-9). Stage 8. MCE Science. Student Book - Unit 8: Forces and Motion - Question 26

A swimmer recorded her practice sessions in one week.

| Day | Distance swum | Time in minutes | Average speed |
|---|---|---|---|
| Monday | 2000 m | 40 | |
| Tuesday | 3000 m | 68 | |
| Wednesday | 2500 m | 50 | |
| Thursday | 3200 m | 64 | |
| Friday | 2000 m | 45 | |

What was the difference between her fastest and slowest speed?

[Response format: give the value in m/min, rounded to 2 decimal places.]