A teacher has partial data of the student result:
The other information available is:
1. Half the students have grade A and B
2. 50% of the students are girls
3. $$\frac{1}{4}th$$ of boys have grade C
Solution
50% of the students are girls. Thus, the total number of students must be 80.
Half the students have grades A and B. This means that 40 students have grades A and B. Now, 30 students have grade B, thus 10 students will have grade A.
Thus, 40 students will have grade C.
5 boys have grade A, and in total 10 students have grade A. Thus, 5 girls will have grade A.
25% of the boys have grade C; thus, 25% of 40 = 10 boys have grade C.
Now, 5 boys have grade A and 10 boys have grade C, and there are a total of 40 students, thus 25 boys will get grade B.
10 boys have grade C, and a total of 40 students got grade C. Thus, 30 girls will get grade C.
25 boys have grade B, and a total of 30 students got grade B. Thus, 5 girls will get grade B.
Total number of girls = 40
Total number of boys = 40
Total students = 80
