A lab technician mixed a 690 ml solution of water and alcohol, if 3% of the solution is alcohol, how many milliliters of alcohol were used and how many milliliters of water were used?

To get the milliliters of alcohol used, we must multiply 690 by 0.03. If we do this, we will get 20.70, which means that 20.70 milliliters of alcohol were used. On the other hand, we can get the milliliters of water used through two ways: the first one is by simply subtracting 20.70 from 690, which will give us the answer 669.30. Another would be by multiplying 690 by 0.97, which will also yield the answer 669.30. The number of milliliters of water used was 669.30.