Question

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

Answer 1

Answer:

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 $x$

Quantity of compound A in milliliter = $5x$

Quantity of compound B in milliliter = $4x$

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

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

$5x+4x=639\\9x=639$

Dividing both sides by 9

$x=71$

Quantity of compound A in milliliter = $5x$ = $5\times71=355\ mililiters$

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