garage parking

[isha]

Yesterday Nan parked her car at a certain parking garage that charges more for the first hour than for additional hour. If Nan's total parking charge at the garage yesterday was $3.75, for how many hours of parking was charged?

1 Parking charges at the garage are $0.75 for the first hour and $0.50 for each additional hour or fraction of hour.
2. If the change for the first hour had been $1.00, Nan's total parking charge would have been $4.00


The answer is A, I had chosen D, I assumed that the charge for additional hours remained same in 2. With the information given in 2 is my assumption wrong ?

[myun]

2. If the change for the first hour had been $1.00, Nan's total parking charge would have been $4.00

The charge for additional hours remain the same, but the hourly rate is not given in the question or in the second condition. We can only figure that the additional charge was 4-1=3 dollars, but that is not enough to compute how many additional hours she parked.

[isha]

Thanks, I just assumed that we know the parking rate for 1st hour when the total was 3.75.