Let's call the total cost for the car rental C.
The daily rental cost is R200, so for 6 days, the rental cost will be 200 * 6 = R1200.
The insurance cost is 7.5% of the daily rental cost, so the insurance cost will be 0.075 * 200 = R15 per day. For 6 days, the insurance cost will be 15 * 6 = R90.
The GPS cost is R45 per day, so for 6 days, the GPS cost will be 45 * 6 = R270.
The additional cost for km driven is 1.8 * 1650 = R2970.
Adding up all the costs, the total cost will be R1200 + R90 + R270 + R2970 = C = R4530