Question

In an examination 30% of the students used unfair means out of which 20%were caught red handed while cheating . If 12 students were caught red handed then find the total no of students.

Answer 1

let total number of student = x

number of student used unfair means = 30% of x = (30/100) × x = 3x/10

number of students caught red handed is 20% of student used unfair means

⇒ number of students caught red handed = 20% of (3x/10)

                                                                      = (20/100)  × (3x/10)

                                                                      = 1/5 × (3x/10) = 3x/50

given that number of students caught red handed = 3x/50 = 12

⇒ x = (12 × 50)/3 = 4 × 50 = 200

Hence total number of students = x = 200