Problema Solution
The costs of a trucking company vary jointly as the number of trucks in service and the number of hours they are used. When 4 trucks are used for 5 hours each, the costs are $1500. Find the costs of using 10 trucks, each for 11 hours.
Answer provided by our tutors
Let
C = the cost of the service
n = number of trucks
t = number of hours
C = k*n*t, where k is constant
When 4 trucks are used for 5 hours each, the costs are $1500:
n = 4 trucks
t = 5 hr
C = $1500
1500 = k*4*5
k*4*5 = 1500
........
........
k = 75
Now we can write the formula for the cost:
C = 75*n*t
n = 10 trucks
t = 11 hr
C = 75*10*11
C = $8,250
The cost of using 10 trucks, each for 11 hours is $8,250.