In an examination, 80% of the students passed in English, 85% in Mathematics and 75% in both English and… · ABC26GN2147
Subject: General Aptitude · Chapter: Percentage
In an examination, 80% of the students passed in English, 85% in Mathematics and 75% in both English and Mathematics. If 40 students failed in both the subjects, find the total number of students.
Answer
No answer key was printed for this question.
Explanation
Let the total number of students be x. Let A and B represent the sets of students who passed in English and Mathematics respectively. Then, number of students passed in one or both the subjects = n (A ∪ B) = n (A) + n (B) – n (A ∩ B) = 80% of x + 85% of x – 75% of x 80 85 75 90 9 = x+ x− x = x= x. 100 100 100 100 10 9x x ∴ Students who failed in both the subjects = x − = . 10 10 x So, = 40 or x = 400. Hence, total number of students = 400. 10
Explanation as extracted from the printed page; notation may be imperfect.