Final answer:
The percent of depreciation for the used car is 30%.
Step-by-step explanation:
To calculate the percent of depreciation for a used car, we need to find the difference between the original cost and the current value, and then divide that difference by the original cost. In this case, the original cost is $1600 and the current value is $1120, so the difference is $1600 - $1120 = $480.
Next, we divide the difference by the original cost: $480 / $1600 = 0.3.
Finally, we convert the decimal to a percentage by multiplying by 100: 0.3 * 100 = 30%.
Therefore, the percent of depreciation for the used car is 30%, which corresponds to option a).