compound and milliters

Question

A certain drug is made from only two ingredients: compound A and compound B. There are 2

 milliliters of compound A used for every 3

 milliliters of compound B. If a chemist wants to make 495

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

Answer 1

Need 495 ml total

2A for every 3B

2A = 3B

A = 3B/2

A+B = 495

3B/2 + B = 495

5B/2 = 495

B = (2/5)495 =2(99)

B=198 ml

A =(3/2)198 = 3(99)= 297 ml

198+297 = 495 ml