The average of the cubes of first nine n

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Target Exam

CUET

Subject

General Test

Chapter

Numerical Ability

Topic

Average

Question:

The average of the cubes of first nine natural numbers is:

Options:

355

360

325

225

Correct Answer:

225

Explanation:

Sum of cube of n natural numbers = n² × \(\frac{(n + 1)(n + 1)}{4}\)

Here n = 9

Sum of cube of 9 natural numbers = 9² × \(\frac{(9 + 1)(9 + 1)}{4}\) = 2025

Now, the average of cube of first 9 natural numbers= \(\frac{2025}{9}\) = 225