Students in math interest groups study math topics. If everyone does 7 questions, there will be 27 fewer questions, and if everyone does 5 questions, there will be 7 fewer questions. Ask how many students there are and how many courses there are. If everyone does 7 questions, 27 questions are missing, 27÷7=3, and the remainder is 6.

It shows that 3 people have no questions to do, 1 individuals have done 1 questions (the rest have 7 questions each).

"Everyone does 5 questions", then "the rest of the people each have 7 questions" will be reduced by 2, which will be distributed to 4 people who have no questions and 1 individuals who have done 1 questions.

"Three people who have no questions to do" are divided into five lanes, *** 15 lanes.

"1 the person who did the 1 question" is divided into four questions.

* * * Required 15+4= 19.

However, "If each person does five questions, there will be seven less questions", then "If each person reduces two questions", it will reduce 19-7= 12.

Then the number of people "doing 7 questions" = 12÷2=6 people.

Then * * * has 6+3+ 1= 10 people.

* * * There are 10×7-27=43 questions.