If you were gonna fill a classroom with milk what would you need to take into consideration?

Does anyone know how to do geometryme with this problem

Reduce fractions expressing probability to lowest terms. in 3,000 repetitions of an experiment, a random event occurred in 500 cases. the expected probability of this event is?

Simplify. 4+3/7x-2-2/7x a. 2-5/7x b. 6-1/7x c. 2+1/7x d. 6+5/7x