Start by converting the capacity of one container into pints. 1 gallon = 4 quarts = 8 pints. 2 quarts = 4 pints. Now add the pints together: 8 + 4 + 1 = 13 pints.
Now multiply the number of pints in one container by 50 to find total number of pints in 50 containers. 13*50 = 650 pints total.
Now convert pints back to gallons, quarts, and pints. Divide 650 by 8 to find maximum number of gallons (the remainder will be written in quarts and/or pints). 8 is the number of pints per gallon:
650/8 = 81R2. That means 650 pints = 81 gallons and 2 pints. 2 pints = 1 quart.
Your final answer is 81 gallons and 1 quart.