Question

There are 5 milliliters of compound A used for every 4 milliliters of compound B. If a chemist wants to make 495 milliliters, how many milliliters of compound A are needed

Answer 1

275

Explanation:

Since there are 4 mm of B for every 5 mm of A that means there are 9 parts in that. Dividing 495 by 9 you get 55 which is how much of each part of the compound there is. Since there are 5 mm of A in each part of A you multiply 5 by 55 to get 275 which is your answer.