Mao Mao took part in the math contest. If you answer a question correctly, you will get 4 points; if you answer a question incorrectly, you will get 1 point. I answered 20 questions and got 60 points. Answered several questions correctly. In order to make you understand, answer slowly!

Assuming everything is done correctly, it should be 4× 20 = 80 points.

If 1 is wrong, subtract 4 points, subtract 1 point and subtract 5 points in * * *, that's 75 points.

1 Every mistake is actually 5 points less; He got 60 points, that is, 20 points less.

Then he got 20 ÷ 5 = 4 wrong questions and 20-4 = 16 right questions.

Checking calculation: 4× 16 = 64 points for doing the right question16, 4 points for doing the wrong question, and 64-4 = 60 points.