Multiple choice

The average age of 40 students of a class is 15 years. When 10 new students are admitted, the average is increased by 0.2 years. Find the average age of the new students.

  1. 15 years

  2. 16 years

  3. 18 years

  4. 20 years
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Total age of 40 students = 40 * 15 = 600. Total age of 50 students = 50 * 15.2 = 760. Sum of ages of 10 new students = 760 - 600 = 160. Average age = 160 / 10 = 16.

AI explanation

The total age of the original 40 students is 40 * 15 = 600 years. When 10 new students join, the new average for all 50 students becomes 15 + 0.2 = 15.2 years, making the new total age 50 * 15.2 = 760 years. The total age of the 10 new students is the difference between the new total and the old total, which is 760 - 600 = 160 years. The average age of the new students is 160 / 10 = 16 years.

Keep practicing — related questions