Question

A certain drug is made from only two ingredients: compound A and compound B. There are 3 milliliters of compound A used for every 4 milliliters of compound B. If a chemist wants to make 533 milliliters of the drug, how many milliliters of compound B are needed?

Answer 1

228.43 ml

Explanation:

The ratio of compound A to compound B will be; 4: 3

4:3 is the same as 4x:3x where 4x is compound A and 3x is compound B.

We can solve for "x":

If amount of compound A is 4x and compound B is 3x;

Then; 4x + 3x = 533

7 x = 533

x = 533/7

Then amount of compound B is 3x = 3(533/7)

= 228.43 ml

Answer 2

`304(4)/(7)\ milliliters`

Explanation:

If there are 3 milliliters of compound A used for every 4 milliliters of compound B, then we can denote that we use 3x milliliters of compound A and 4x milliliters of compound B to get 533 milliliters of the drug. Thus,

`3x+4x=533,\\ \\7x=533,\\ \\x=(533)/(7)\ milliliters.`

Hence, a chemist must take

`4\cdot (533)/(7)=(2132)/(7)=304(4)/(7)\ milliliters`

of compound B.