In a class, 60% of the students are girls and the rest are boys. There are 30 more girls than boys. If 68% of the students, including 30 boys, pass an examination, what is the percentage of the girls who do not pass?
Let the total number of students =T
0.40T + 30 =0.60T, solve for T
T = 150 total number of students.
0.6 x 150 =90 are girls
0.4 x 150 =60 are boys.
0.68 x 150 =102 students, which includes 30 boys, passed the exams.
102 - 30 boys = 72 girls who passed the exams.
90 girls - 72 girls = 18 girls who did NOT pass the exams.
18 girls / 150 students = 12% of the girl students who did NOT pass the exams.
OR: 18 girls /90 girl students =20% of ALL girls in school did NOT pass the exams.
