the cafeteria chef fixed bag lunches for a field trip. he made 1/3 of the sandwiches with peanut butter and je?

Reword your question, it's more like an unfinished statement ..

Wow, your cafeteria has a chef.
Umm, yes, 1/3 of the sndwiches are peanut butter and jelly.
Two thirds, 2/3, the remainder are something else.

This will never happen because there is one kid in the 3rd grade who has peanut allergy so the 7th grade field trip must be forbidden from having peanut butter sandwiches.