Answer:
8 min
4 min
6 min
The second gardener trimmed the fastest
Explanation:
You have to divide the amount of time by the number of bushes for each gardener.
First gardener: 72min / 9 bushes = 8min/bush
Second gardener: 20min / 5 bushes = 4min/bush
Third gardener: 48 min / 8 bushes = 6min/bush