To reduce 16 ounces of a 25% solution of antiseptic to a 10% solution, how much distilled water should a nurse add?

24 ounces

Step-by-step explanation:

Here's a more intuitive approach to use here.

You know that your initial solution has a percent concentration, presumably volume by volume, of  

25

%

. This means that any volume of this solution contains  

1

part solute and  

3

parts solvent.

The target solution must have a concentration of  

10

%

, which means that any volume of this solution will contain  

1

part of solute and  

9

parts solvent.

Your starting solution has a volume of  

16

ounces, or  

4

parts, each with a volume of  

4

ounces.

In order to get to a solution that has a total of  

10

parts, you must add  

6

parts of solvent to the initial solution. Since we know that

1 part  

=

4 ounces

it follows that you must add

6

parts

⋅

4 ounces

1

part solvent

=

24 ounces

of distilled water, which is your solvent, to the initial solution.

The target solution will contain  

1

part solute and  

9

parts distilled water for a total of  

10

parts of solution, and hence have a percent concentration of  

10

%

.

7. d. 64

8. i. 32

9. c. 125

10. j. none of the above

11. d. 81

12. i. 216

13. e. none of the above

14. g. 240

15. e. none of the above

16. g. 32

17.   e. none of the above

answer: the four apples you took away.

step-by-step explanation: