A chemist is using 336 milliliters of a solution of acid and water. If 15.6%

of the solution is acid, how many milliliters of acid are there? Round your answer to the nearest tenth.

"A chemist is using 336 millilitres of a solution of acid and water."

This sentence implies that the solution only contains acid and water.

Now, we are told:

"15.6% of the solution is acid."

What is 15.6% percent though, as a decimal?

Well, 15.0% is actually equal to 0.15 as a decimal. 0.6% is actually 3/5 of 1%, which in turn is 3/5 of 0.010 which is 0.006 as a decimal.

So, we now know that 15.6% is actually equal to 0.156 as a decimal.

Let's multiply 0.156 by 336 to get our answer.

0.156 x 336 = 52.4 (rounded to the nearest tenth)

There are 52.4 millilitres (to the nearest tenth) of acid in the solution.