in the lab, tom has two solutions that contain alcohol and is mixing them with each other. he uses 300 millilters less of solution A than solution B. solution A is 10% alcohol and solution B is 13% alcohol. How many millilters of solution B does he use, if the resulting mixture has 269 millilters of pure alcohol?

To find the amount of solution B used, we can start by assigning variables to the unknowns. Let's say the amount of solution B used is x milliliters.

Since Tom uses 300 milliliters less of solution A than solution B, the amount of solution A used would be (x - 300) milliliters.

Now, let's calculate the total amount of alcohol in the resulting mixture:

The amount of alcohol in solution A = (x - 300) * 0.10
The amount of alcohol in solution B = x * 0.13

Since the resulting mixture has 269 milliliters of pure alcohol, we can set up the following equation:

(x - 300) * 0.10 + x * 0.13 = 269

Now we can solve for x:

0.10x - 30 + 0.13x = 269
0.23x - 30 = 269
0.23x = 299
x = 299 / 0.23
x ≈ 1,300

So, Tom used approximately 1,300 milliliters of solution B.

let Vb be the volume of solution B

Va*.1+Vb*.13=269

(Vb-300)*.1+Vb*.13=269
solve for Vb