Let 8 milliliters of compound A and 5 milliliters of compound B be a mixture.
We can then find how many mixture is needed for 845 milliliters of the drug by dividing it by (3+5=8):
736 ÷ 8
=92
As 65 mixture is used and each mixture include 5 milliliters of compound B, we can find the amount of compound B by multiplying 92 by 5
92 x 5
=460 milliliters
Therefore the answer is 460 milliliters.
Hope it helps!