There are only two questions in the math exam. Results The whole class 10 was all right, the first question was all right for 25 people, and the second spoon was wrong for 18 people. How many people are there in the class? There are ***x people in the class, and there are y people who have done both questions wrong.

25 people answered the first question correctly and 10 people answered the second question correctly, so only 25- 10= 15 people answered the first question correctly.

There are 18 people who made mistakes in the second question and (x- 18) people who made mistakes. Among them, the first question 10 was also done correctly, that is, only (x- 18)- 10 was done correctly.

10 The person who answers both questions correctly.

Y-man of two wrong problems

***x people in total.

x = 10+y+ 15+[(x- 18)- 10]

The total number of students in the class = two questions right+two questions wrong+only the first question right+only the second question right.

Solve y=3, that is, there are always ***3 people, and both questions are wrong.