Harold made 2 3/4 liters of lemonade. He drank 1/4
of a liter of the lemonade. Then, he poured the remaining lemonade equally into 6 cups. How much lemonade did Harold pour into each cup?
Harold drank 1/4 liter of the lemonade, so he had 2 3/4 - 1/4 = 2 1/2 liters of lemonade left.
To find out how much lemonade Harold poured into each cup, divide 2 1/2 liters by 6 cups.
Since 1 liter is equal to 4/4 liters, then 2 1/2 liters is equal to (2*4+1)/2 = 9/2 liters.
Then, Harold poured 9/2 / 6 = 9/2 * 1/6 = 9/12 = 3/4 liter of lemonade into each cup. Answer: \boxed{\frac{3}{4}} liters.