Question

RSM a pharmisest has a 18 percent alcohol sulution and a 40 percent alcohol sulution how much of each must he use to make 10 leaters of 20 persent alcohol sulution

Answer 1

To make 10 liters of 20% alcohol solution, RSM would need to use a combination of the 18% and 40% alcohol solutions. Let's call the amount of 18% solution used "x" and the amount of 40% solution used "y".

To set up the equation, we'll use the fact that the amount of pure alcohol in the final solution must be equal to 20% of the total volume.

So:

0.18x + 0.40y = 0.20(10)

Simplifying:

0.18x + 0.40y = 2

We have one equation with two unknowns, which means we need another equation. Fortunately, we know that RSM is making a total of 10 liters of solution. So:

x + y = 10

We now have two equations with two unknowns, which we can solve simultaneously. One way to do this is to solve one equation for one variable, then substitute that expression into the other equation, like so:

x = 10 - y (from the second equation)

0.18(10-y) + 0.40y = 2 (substituting into the first equation)

1.8 - 0.18y + 0.40y = 2

0.22y = 0.2

y = 0.91

So RSM would need to use approximately 0.91 liters (or 910 milliliters) of the 40% solution, and the rest (9.09 liters or 9090 milliliters) of the 18% solution, to make 10 liters of 20% alcohol solution.