To find the number of students with red hair, we need to subtract the percentage of students with brown hair and black hair from 100% (since these two groups make up the majority of the students).
Let's calculate the number of students with brown hair first.
34% of 80 students is (34/100) * 80 = 27.2 students. Since we can't have a fraction of a student, we round it to the nearest whole number. So, there are approximately 27 students with brown hair.
Next, let's calculate the number of students with black hair.
61% of 80 students is (61/100) * 80 = 48.8 students. Again, rounding it to the nearest whole number, we have approximately 49 students with black hair.
Now, let's subtract the total number of students with brown and black hair from the total number of students to find the number of students with red hair.
Total students = 80
Students with brown hair = 27
Students with black hair = 49
Students with red hair = Total students - (Students with brown hair + Students with black hair)
Students with red hair = 80 - (27 + 49) = 80 - 76 = 4
Therefore, the correct answer is B. 4 students have red hair.