Reconstruct a question, answer pair from this explanation: Louie got 100% - 80% = 20% of the total items incorrect, which is equal to 5 items. So 1% is equal to 5 / 20 = 1 / 4 of an item. Hence, the total number of items, represented by 100%, on the math quiz was 1 / 4 of an item x 100 = 25.
Q:Louie obtained 80% on a math quiz. He had 5 mistakes. How many items were there on the math quiz?
A:25