The average age of a group of 24 students is 15 years. If a student aged 9 years leaves the group, what will be the new average age?
Show answer & explanation
Correct answer: C
Explanation
Average age of 24 students = 15 years
Total age = 24 × 15 = 360
New total age = 360 − 9 = 351
New number of students = 24 − 1 = 23
New average age = 351 ÷ 23 ≈ 15.26 years