What is the difference between the longest and the shortest pencil

Answeron:

Du plus gras au plus sec : 9b - 8b - 7b - 6b - 5b - 4b - 3b - 2b - B - HB - F - H - 2h - 3h - 4h - 5h - 6h - 7h - 8h - 9h

answer: all of the odd numbers were opened

the first person was the one that was opening all of the lockers. since one is odd, this causes all of the odd number lockers to be opened in the end.

this may not be at all, but i use the same website you're using for school, and if i'm stuck doing one of these i try to look for it on the section.