The number of students of girls in a certain junior high school is 95% of the number of students of boys.
The number of absentees on a certain day were four and all of them were girls.
The ratio of the number of girls' attendant in this day became 11/12 of the boy.
Find the number of all students of this junior high school.
Answer
234 persons
Solution
The number of boys is set to be X.
X : X × 0.95 - 4 = 12 : 11
X × 12 × 0.95 - 48 = X × 11
Thus X × 0.4 = 48
Then X = 120.
Therefore the number of all students is 120 + 120 × 0.95 = 120 + 114 = 234 persons.
