Let Xiaohong be on the right track of X. It can be seen from the question that the score of 1 is 5 points. Assuming there is nothing wrong, only doing it right or not, then the score must be a multiple of 5. And Xiaohong got 73 points, which means Xiaohong got an x multiplied by 5, and then there were 1 errors, and n must be an odd number. That is, 5x-2=73, and x= 15 is obtained. The total number of questions is 20, so the number of questions not done is equal to 20- 1- 15=4. In other words, 15 is right, 1 is wrong, and 4 is not done.