Joseph wants to earn $850 this summer in order to pay for a down payment on a car. His summer break is 6 weeks. He has been offered 3 different jobs.

Which job should he take to earn the $850 quickest? Explain your response.
Working as a cashier in a bookstore that pays $7.50 an hour and he is expected to work 25 hours per week

Working at a summer camp as a camp counselor for a flat rate of $175 per week (the camp is only 4 weeks)

Working as a sales associate at a department store that pays $7.25 an hour with 5% commission on all sales (he is expected to work 20 hours per week and projected to sell $1,350 per week)
B. Which job will not help him get to his goal of $850?