Question

NEED HELP ASAP

So for this problem I got 10.8 by multiplying 0.60 x 18. However it stated that my answer is incorrect. How do I go about this problem because I am not sure what else to do?

Answer 1

upandover has a great solution. Here's a slightly different approach.

x = total amount of solution (consisting of water and alcohol mixed)

0.60x = 60% of x = amount of pure alcohol

0.60x = 18 since we have 18 mL of pure alcohol

Divide both sides by 0.60 to isolate x

0.60x = 18

x = 18/0.60

x = 30

Answer: 30 mL of total solution (alcohol + water).

Answer 2

We are looking for the total amount of the solution. We only know part of it, that there are 18 milliliters of the alcohol. We also know that the alcohol makes up only 60% of the solution.

To find the whole, we can set up a proportion using the information given.

60 / 100 <--- This is our percentage, which we were given.

18 / x <--- This is the part (alcohol - 60%) over the whole, which we don't know and which also corresponds to the 100.

Therefore, our proportion is as such:

60 / 100 = 18 / x

To solve, cross-multiply.

100 * 18 = 60 * x

1800 = 60x

x = 30 total milliliters of the solution

Hope this helps!