Answer:
5 hours
Step-by-step explanation:
Given that :
Juan:
Rate = 12mi/hr
$9.75/mi
Carlos :
Rate = 10mi/hr
$11.50/mi
To raise atleast $1000 altogether :
Let number of hours = h
Distance = rate * time
[(12*h) * 9.75] + [(10*h) * 11.50] ≥ 1000
[117h + 105h] ≥ 1000
222h ≥ 1000
h ≥ 1000/222
h ≥ 4.504
To earn atleast $1000 altogether, they must work for atleast 5 hours (nearest whole number).