Hi there!
Using some simple conversions we can determine how many quarts are in 2 & a half gallons.
1 gallon = 4 quarts.
2 gallons = 8 quarts.
Since we're trying to determine how many quarts are in 2 & a half gallons we can separate our problem into how many quarts are in two gallons and how many are in a half a gallon.
2 gallons = 8 quarts.
.5 gallon = 2 quarts.
After adding this together we come up with the answer that there are 10 quarts in 2 & a half gallons. :)