Some food is able to keep 150 students fed at camp for 5 days, How many days will the food last for if there are 100 students,

I know its 7.5 but why do people x the 150 and 5 i dont get it

This is what i found “an explicit formula designates the nth term of the sequence, as an expression of n (where n = the term's location). it defines the sequence as a formula in terms of n. this example is an arithmetic sequence(the same number, 5, is added to each term to get to the next term).” i hope this you for what your looking for. can you plz mark me brainliest?