You need a 25% alcohol solution. On hand, you have a 325 mL of a 20% alcohol mixture.
You also have 50%
alcohol mixture. How much of the 50% mixture will you need to add to obtain the desired solution?

You will need


mL of the 50% solution



Answer :

We need 65 ml of 50% mixture to obtain the desired solution.

Here, we need to make a 25% alcohol solution by mixing some amount of 50% alcohol mixture with 325 mL of a 20% alcohol mixture.

Let the amount of 50% alcohol solution be x

The the quantity of alcohol in 50% alcohol solution = 50% of x

= 0.5x

Similarly the the quantity of alcohol in 20% alcohol solution = 20% of 325

= 65ml

The total quantity of 25% alcohol solution = (325 + x) ml

Thus, the the quantity of alcohol in 25% alcohol solution = 25% of (325 + x)

= 0.25 (325 + x)

= 81.25 + 0.25x

Thus, we can form the following equation-

0.5x + 65 = 81.25 + 0.25x

0.5x - 0.25x = 81.25 - 65

0.25x = 16.25

x = 16.25/ 0.25

x = 65

Thus, we need 65 ml of 50% mixture to obtain the desired solution.

Learn more about weighted averages here-

https://brainly.com/question/24398353

#SPJ9