A certain drug is made from only two ingredients: compound A and compound B. There are 5 milliliters of compound A used for every 4 milliliters of compound B. If a chemist wants to make 639 milliliters of the drug, how many milliliters of compound A are needed

355 milliliter.

Step-by-step explanation:

Given:

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

There are 5 milliliters of compound A used for every 4 milliliters of compound B.

If a chemist wants to make 639 milliliters of the drug, how many milliliters of compound A are needed ?

Solution:

As 5 milliliters of compound A is used for every 4 milliliters of compound B.

Ratio of compound A and compound B = 5 : 4

Let ratio be

Quantity of compound A in milliliter =

Quantity of compound B in milliliter =

Now, we have to make 639 milliliters of the drug,

Quantity of compound A + Quantity of compound B =  639 milliliters

Dividing both sides by 9

Quantity of compound A in milliliter = =

Therefore, 355 milliliter of compound A are needed to make 639 milliliters of the drug.

10 b/c 5*2 =10

step-by-step explanation:

he earned 78.75 in interest.

step-by-step explanation: