57.4 millilitres
We know that the chemist has 332 milliliters of the solution of acid and water, and 17.3% of that solution is acid.
We can then persume that the amount of acid in the solution is equal to 332ml × 17.3%
This is equal to 57.436ml.
Then the question states to round the answer to the nearest tenth.
Rounding 57.436ml to the nearest tenth (.1) will equal to 57.4ml.
Therefore, there are 57.4ml of acid in the solution rounded to the nearest tenth.