Find the average of cubes of natural num

CUET Preparation Today

Start Free Mocks

Home Questions F2JT67924A

Target Exam

CUET

Subject

General Test

Chapter

Numerical Ability

Topic

Average

Question:

Find the average of cubes of natural numbers till 7.

Options:

115

110

112

140

Correct Answer:

112

Explanation:

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

Here n = 7

Sum of cube of 7 natural numbers = 7² × $\frac{(7 + 1)(7 + 1)}{4}$ = 784

Now, the average of cube of first 7 natural numbers= $\frac{784}{7}$ = 112