They're already in that order.
The number "10Qt" likely stands for 10 quintillion, which is equal to 10,000,000,000,000,000,000.
3gal
10 quarts is 40 cups.
10 quarts is 2.5 US gallons.
Ten quarts (10 qt) is equivalent to 2.5 gallons, as there are 4 quarts in a gallon. It is also equal to approximately 9.46 liters. In terms of pints, 10 quarts equals 20 pints, since there are 2 pints in a quart.