50 students = 7 have red hair
100 students = 14 have red hair
150 students = 21 have red hair
200 students = 28 have red hair
250 students = 35 have red hair
300 students = 42 have red hair
<h2>↓ ↓</h2>
600 students = 84 have red hair
650 students = 91 have red hair
700 students = 98 have red hair
750 students = 105 have red hair
Therefore, around 105 students would have red hair out of all the students in the school.
