College Math Question

Question

A certain drug is made from only two ingredients: compound A and compound B. There are 8

 milliliters of compound A used for every 5

 milliliters of compound B. If a chemist wants to make 1287

 milliliters of the drug, how many milliliters of compound A are needed? 

Answer 1

If we have an 8:5 ratio, then we know that 8/13 of the total result will be A, and 5/13 will be B.

So the amount of compound A will be (8/13) * 1287, which is 792 ml.