Math  /  Algebra

Question7. A 30%30 \% antifreeze solution is mixed with a 15%15 \% antifreeze solution to obtain 24 gallons of a 25%25 \% antifreeze solution. Find xx, the number of gallons 30%30 \% antifreeze solution used. Round to the nearest gallon, if necessary. 24q=25%24 q=25 \%

Studdy Solution

STEP 1

What is this asking? We're mixing two antifreeze solutions with different concentrations to create a specific amount of a new solution, and we need to figure out how much of each original solution we used! Watch out! Don't mix up the amounts of each solution with their concentrations – those percentages are key!
Also, keep track of your units (gallons) throughout.

STEP 2

1. Set up the mixture equation
2. Solve for xx

STEP 3

Let xx be the number of gallons of the **30%** antifreeze solution.
Since we want a total of **24 gallons**, the amount of the **15%** solution will be 24x24 - x gallons.

STEP 4

The **30%** solution contributes 0.30x0.30 \cdot x gallons of pure antifreeze.
The **15%** solution contributes 0.15(24x)0.15 \cdot (24 - x) gallons of pure antifreeze.
And our desired **24-gallon** mixture contains 0.25240.25 \cdot 24 gallons of pure antifreeze.

STEP 5

The total amount of antifreeze from the two initial solutions *must* equal the amount of antifreeze in the final mixture!
So, our equation is: 0.30x+0.15(24x)=0.25240.30x + 0.15(24 - x) = 0.25 \cdot 24

STEP 6

Let's distribute and combine like terms: 0.30x+3.60.15x=60.30x + 3.6 - 0.15x = 6 0.15x+3.6=60.15x + 3.6 = 6

STEP 7

Subtract **3.6** from both sides of the equation: 0.15x+3.63.6=63.60.15x + 3.6 - 3.6 = 6 - 3.6 0.15x=2.40.15x = 2.4

STEP 8

Divide both sides by **0.15** to find xx: x=2.40.15x = \frac{2.4}{0.15} x=16x = 16

STEP 9

We need **16 gallons** of the **30%** antifreeze solution.
Since we need a total of **24 gallons**, we'll also need 2416=24 - 16 = **8 gallons** of the **15%** solution.

Was this helpful?

Studdy solves anything!

banner

Start learning now

Download Studdy AI Tutor now. Learn with ease and get all help you need to be successful at school.

ParentsInfluencer programContactPolicyTerms
TwitterInstagramFacebookTikTokDiscord