I'll give you a question, please answer with step-by-step reasoning process.
Felix is chopping down trees in his backyard. For every 13 trees he chops down he needs to get his axe resharpened. It cost him $5 to sharpen his axe. If he spends $35 on axe sharpening, at least how many trees has he chopped down?

91
He has sharpened in 7 times because 35 / 5 = 7.

He has chopped down 91 trees because 7 x 13 = 91.

.

The final answer: 91