The mean of 12 22 32 42 52 62 72 is…

Are you looking for correct answer of The mean of 12 22 32 42 52 62 72 is…? Here we have shared detailed answer with explanations.

The mean of 12, 22, 32, 42, 52, 62, 72 is –

  1. A. 10
  2. B. 20
  3. C. 30
  4. D. 40

Answer: Option B

Here is complete explanation of The mean of 12 22 32 42 52 62 72 is….

Solution(By ExamCraze Team)

12 + 22 + 32 + . . . . . + n2 = $$frac{{nleft( {n + 1} right)left( {2n + 1} right)}}{6}$$
∴ 12 + 22 + 32 + . . . . . + 72 = $$left( {frac{{7 times 8 times 15}}{6}} right)$$   = 140
So, required average
$$ = left( {frac{{140}}{7}} right)$$
= 20

Leave a Comment