Answer: 216 millilitres
Explanation:
From the question, you are given that there are 3 milliliters of compound A used for every 5 milliliters of compound B. That means compound A and B are in ratio 3 to 5. That is,
A : B = 3 : 5
If a chemist wants to make 576 milliliters of the drug, then find the ratio of compound A.
To do that, first add the ratio of both together, 3 + 5 = 8
For compound A,
3/8 × 576
1728/8 = 216 millilitres
Therefore, 216 millilitres of compound A are needed.