Hi.
This is definitely a confusing question - don't worry, though. I'll explain it.
We want to find out how many hours in total he did during that time, so we can divide the total number of laps by the total in hours.
[tex] \frac{45}{60} = 0.75[/tex]
0.75 · 5 · 12 = 45 hours total
[tex] \frac{1800}{45} = 40[/tex]
Sebastian's rate was 40 laps per hour.
Cheers!
