Yesterday, Nan parked her car at a certain parking garage

Hi,
Posting this OG question here for discussion. I don't quite agree with the OA due to some lines in the question which I think the explanation overlooked. ( Or I read too deeply into it). Anyway, here it is:

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

(1) Parking charges at the garage are $0.75 for the first hour and $0.50 for each additional hour or fraction of an hour.

So for the first hour--> $0.75
Each additional hour --> $0.50
We've met the question's statement "charges more for the first hour than each additional hour", but that's not important.

Since for the first hour it's $0.75, so $3.00 must be incurred by the number of hours parked after the first hour. But we are told that $0.50 is charged for each additional hour OR fraction of an hour, so we can't tell if she parked for 3.00/0.50 = 6 hours, or 5.5 hours with the last fraction of an hour (0.5 in this case) still incurring a 50cents charge.
So statement 1 should be insufficient.

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

Not sufficient as we're not told the hourly rate after the first hour.

Combining (1) and (2) still does not answer the niggly question of whether she parked fraction or whole hours. So I picked (E) which the Oa disagrees with.

What do you guys think ?