Averages · Question 30 · Hard
What is the average of the squares of the first 12 natural numbers?
- 42 1/4
- 54 1/6
- 50
- 72
Answer and explanation
Answer: B. 54 1/6
Explanation: Sum of squares = n(n + 1)(2n + 1)/6 = 12 × 13 × 25/6 = 650. Average = 650/12 = 54 1/6.
Previous: Of four numbers, the average of the first three is 16 and the average of the…
Practise averages
Try a fresh set of averages questions with an explanation after every answer, free and without signing up: Averages practice. Or sit a full placement mock test.
More averages questions
- A batter's average in 20 innings is 40. The difference between the highest and…
- Three years ago, the average age of a family of 5 members was 25 years. A baby…
- Of four numbers, the average of the first three is 16 and the average of the…
More quantitative aptitude practice
Problems on Ages · Mixtures & Alligation · Time & Work · Pipes & Cisterns · Time, Speed & Distance · Problems on Trains · Boats & Streams · Permutation & Combination
LogicWiz Exams home · All practice topics · Placement mock tests · Daily 10 challenge