Question

A pharmacist has an 18% alcohol solution. How much of this solution and how much water must be mixed together to make 10 liters of a 12% alcohol solution?

Answer 1

To make a 10 liter solution of 12% alcohol, you need to mix 6.67 liters of an 18% alcohol solution with 3.33 liters of water.

Step-by-step explanation:

To make a 12% alcohol solution, we need to mix the 18% alcohol solution with water. Let's assume x liters of the 18% alcohol solution and (10 - x) liters of water.

The amount of alcohol in the 18% solution is 0.18x liters, while the amount in the water is 0 liters. In the final solution, the amount of alcohol is 0.12 * 10 = 1.2 liters.

So, we can set up the equation 0.18x + 0 = 1.2 and solve for x. By solving this equation, we find that x = 6.67 liters. Therefore, 6.67 liters of the 18% alcohol solution and 3.33 liters of water should be mixed to make 10 liters of a 12% alcohol solution.

Answer 2

`6(2)/(3)` of 18%,
`3(1)/(3)` water

Step-by-step explanation:

The 18% solution added to the water is equal to the 10 liters of 12% solution.

Let's say that the amount of 18% solution is x

18% of x = 0.18x

Let's say that the amount of water is 10-x

Because there is no alcohol in water, it will be 0(10-x), or just 0

0.18x + 0 = 10•0.12

0.18x = 1.2

x =
`6(2)/(3)`

10 -
`6(2)/(3)` =
`3(1)/(3)`