I think there 1 and 1/2 quarts of lemonade left in the pitcher because in 1 quart there is 4 cups of something. In one gallon there are 4 quarts. So in one gallon there are 16 cups. How I got 16 cups it’s easy (4+4+4+4) . So they drank 5 glasses and each glass is 2 cups. So it will be 10 cups. (2+2+2+2+2). So in one gallon 16 cups they drank 10 cups. 6 cups left. 4 cups one quart and 2 cups is 1/2 of one quart. So the answer is 1 and 1/2 quarts of lemonade. Thank you
