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.
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-> 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.
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Question 971925: 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 by Boreal(15235) (Show Source):
You can put this solution on YOUR website! joint variability
4 trucks*5 hours cost $1500. It is 20 truck-hrs. or $75 (1500/20) per truck-hr.
10 trucks *11 hours is 110 truck-hrs. The cost would be $75 * 110=$8250.
It is 2.5 times the number of trucks and 2.2 times the number of hours.
Joint variability is multiplying by both, which is here 2.5*2.2=5.5
$1500*5.5=$8250.
