The average age of 20 students is 18 years. A group of 5 new students joins, increasing the average to 20 years. Find the average age of the 5 new students.
Show answer & explanation
Correct answer: C
Explanation
Initial number of students = 20
Average age = 18 years
Number of new students = 5
New average = 20 years
Total age of the initial 20 students = 20 × 18 = 360
Total number of students now = 25
Total age = 25 × 20 = 500
Total age of the 5 new students = 500 − 360 = 140
Average age = 140 / 5 = 28 years