Multiple choice

There are 30 students in a class. The average age of the first 10 students is 13.5 years. The average age of the next 20 students is 14.1 years. What is the average age of the whole class?

  1. 13.0 years

  2. 13.5 years

  3. 13.7 years

  4. 13.9 years

  5. 13.8 years

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Total age of 10 students = 13.5 * 10 = 135 years. Total age of 20 students = 14.1 * 20 = 282 years. Average age of 30 students = (135 + 282)/30 = 13.9 years Therefore, it is the correct answer.