Answer:
A
Step-by-step explanation:
2 times 8 x 12
192
2 times 5 x 8
80
2 times 12 x 5
60
192+80+60=332 ft^2
So,

Write in prime factored form.

Cross-cancel
The diameter is 16 its double
So what you do first is find the area of this lawn and you do 10 by 12 and multiply those and you get 120 feet so now what you do is divived 120 by 3 and you get 40 so that means she mowed 40 ft in each hour so that would be the unit rate.