Answer:
33 students
Explanation:
Without any other data to go by, guess and check is the only method we can use. Staying in a 4:7 ratio, only one combination gives a total student number between 24 and 40, with 12 boys and 21 girls.
4 + 7 = 11
8 + 14 = 22
12 + 21 = 33
16 + 28 = 44