A 400-milliliter solution of a fabric dye contains 8 ml of hydrogen peroxide. What is the percent concentration of the hydrogen peroxide?

Okay so all you need to know is the percentage of the hydrogen peroxide.
We know that the total solution is 400 ml and the hydrogen peroxide solution is 8ml.
8/400

Percent means out of a hundred, this can go multiple ways.

Way #1, benchmarking.

So 8/400 simplified is 1/50 or 2/100.
1/50 is basically 2/100.

And percent means out of a hundred so 2/100 is basically 2percent.

Way #2, proportions

We want to know the percentage of hydrogen/ fabric dye

If you put it in numbers int he same fraction and put “x” as the unknown 8ml hydrogen peroxide solution you’d get.

8/400 = x/100
X/100 because percent means out of a hundred.
Now solve3

Cross multiply,

800 = 400x
divide 400 on both sides

2=x

Now plug it back in the proportion.

8/400 = 2/100

If you simplify to check if they are equal then it’s correct