If all 20 questions are correct, you can get 20×5= 100 points. If you answer the wrong question, you won't get the original 5 points, but you will also be deducted 3 points. It can be seen that1* * is less than 5+3=8 points, so it can be seen that,

( 100-52)÷(5+3)=48÷8=6

20-6= 14

Correct answer 14, wrong 6.