Elementary Algebra

Published by Cengage Learning
ISBN 10: 1285194055
ISBN 13: 978-1-28519-405-9

Chapter 3 - Equations and Problem Solving - 3.5 - Problem Solving - Problem Set 3.5: 28

Answer

We must add 150 ml of distilled water.

Work Step by Step

Let X represent the amount of water to be added. After X is added, we obtain a 10% acid solution. A 40% acid solution has 60% water in it. A 10% acid solution has 90% water in it. We use the following guideline to solve this problem: Amount of water in original solution + Amount of water to be added = Amount of water in final solution. 60% $\times$ 50 + X = 90% $\times$ (50 + X) $.6 \times 50 +X = .9 \times (50+X)$ 30 + X = 45 + $\frac{9X}{10}$ $\frac{10X}{10}$ - $\frac{9X}{10}$ = 15 $\frac{X}{10}$ = 15 Multiply both sides by 10. X = 150 We must add 150 ml of distilled water.
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.