URGENT!
A scientist begins an experiment with 20.25 milliliters of a chemical. She adds 0.75 milliliter of water to the chemical every 10 minutes, starting at 1:30 P.M.
The scientist continues adding the 0.75 milliliters to the mixture until amount of chemical and water are EQUAL. At that point she uses 2/3 of the mixture for further experiments.
How many milliliters of the mixture are unused?
