Answer:
Kevin's weekly sales will have to be worth more than $4000 in order for Dollar Deal to pay more.
Step-by-step explanation:
Dollar Deal offers $8/h plus 10% commission.
If he spends x hours, then offer after x hours and s amount from sales is;
8x + 10%s
This can be rewritten as; 8x + 0.1s
Now, Great Discounts offers $18/h with no commission.
Thus after 8 hours for 5 days, total number of hours = 40 hours.
Thus, great discounts offer = 18 × 40 = $720
Now, dollar deal will offer; 8(40) + 0.1s = 320 + 0.1s
Thus, for dollar deal to pay more weekly, then;
320 + 0.1s > 720
0.1s > 720 - 320
0.1s > 400
s > 400/0.1
s > 4000
