Can someone just check my answers please? Please let me know which questions are wrong. Thank you for your time.

Answers:

You got the first question correct, but the second one is wrong. The two values must add up to 5.

Explanation:

We're told that 20% of this solution is acid. We have 5 liters total, so

20% of 5 = 0.20*5 = 1

Meaning there's 1 liter of pure acid in this solution.

The remaining 5-1 = 4 liters of the solution is water

Or you could note that if 20% is pure acid, then the remaining 80% is water

80% of 5 = 0.80*5 = 4

Another approach is to realize that 20% is the same as the fraction 1/5

So if 1/5 of the mix is pure acid, and we have 5 liters of the solution, then we must have 1 liter of pure acid

(1 liter of pure acid)/(5 liters of solution) = 1/5 = 20% acid solution

I think they all look pretty good for the most part

b) 36

step-by-step explanation:

18 times 2 is 36