Question

a class of $30$ students, exactly $7$ have been to Mexico and exactly $11$ have been to England. Of these $30$ students, $4$ have been to both Mexico and England. How many students in this class have not been to Mexico or England?

Answer 1

16

Explanation:

Answer 2

16

Explanation:

Of the 7 students that have been to Mexico, 4 have also been to England. Therefore, 7-4=3 students have been to Mexico and not England.

Of the 11 students that have been to England, 4 have also been to Mexico. Therefore, 11-4=7 students have been to England and not Mexico.

Therefore, 3 students have been to Mexico only, 7 students have been to England only, and 4 students have been to both. In the class of 30 students, this leaves
`$30-3-7-4=\boxed{16}$` students who have not been to Mexico or England.

Hope this helped! :)