Question

John has a job parking cars. He eams a fixed weekly salary of $260 plus a fee of $A for each car he parks. His potential earnings for a week are shown in the graph. At what point does John begin to earn more from fees than his fixed salary? Complete the justification of your answer. Earnings 675 600 525 Weekly Earnings 375 150 Cars parked 10 20 30 70 30 100 John earns the same in fees as his fixed salary when he parks fee per car= cars. He starts earning more from fees than his salary when he parks cars.

Answer 1

Jhon earns the same in feeds as his fixed salary when he parks $260/$4 fee per car =65 cars. He starts earning more money from fees that his salary when he parks 66 cars.

`4C\ge260\Rightarrow C\ge65`

So from the above deduction we can see that John will earn the equal amount of his weekly pay after he parks 65 cars. Then it becomes obvious that parking car number 66, John will start earning more than what he gets as his fixed weekly salary. I hope you have understood the described method.