Multiple choice

Find the average of following term- 512 + 729 + 1000 ------- + 15625

  1. 5824.5

  2. 5421.5

  3. 5084.25

  4. 4921.5

  5. 6015.25
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Terms are cubes from 8³ to 25³. Use sum of cubes formula: [n(n+1)/2]². Sum 1³ to 25³ = (25×26/2)² = 325² = 105625. Sum 1³ to 7³ = (7×8/2)² = 28² = 784. Required sum = 105625-784 = 104841. Number of terms = 25-8+1 = 18. Average = 104841/18 = 5824.5. Options B, C, D, E are calculation errors.

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