Final answer:
To find the greatest number of students that could be in each row with the condition that only girls or boys will be in each row, determine the total number of girls and boys and calculate the highest common factor (HCF) for both.
Step-by-step explanation:
The question pertains to arranging a choir in rows with the condition that only girls or boys will be in each row. To determine the greatest number of students that could be in each row, the choir teacher would need to first identify the total number of students and then find the highest common factor (HCF) applicable to both the number of girls and boys. This is because the greatest number of students per row, where each row has either just boys or just girls, would need to divide evenly into both the total number of girls and the total number of boys. If, for example, there are 60 girls and 75 boys, the HCF of 60 and 75 is 15, meaning the teacher could arrange the students into rows of 15 while maintaining the condition.