Answer & Step-by-step explanation:
To find the total rental cost, we need to add the flat fee to the mileage charge. Here are the steps:
1. Multiply the number of rental days by the flat fee: 3 days x $25/day = $75
2. Multiply the total miles driven by the mileage rate: 150 miles x $0.20/mile = $30
3. Add the flat fee and the mileage charge to get the total cost: $75 + $30 = $105
Therefore, the customer's total rental cost is $105.
Hope it helps!