Maria was always top of the class in math. She is still very good at math, but if she wants to be top of the class again, she will have to take extra lessons and spend even more time doing math problems. The tutoring costs 45 euros per hour and she expects with 1 hour of tutoring per week to be the best again within two months and her estimate appears to be correct. The total cost of the tutoring is much higher than her parents expected.
Inference
Maria spent virtually no time on math before losing her position as best student in the class.