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Consider the following statements : 1. The sum of cubes of first 20 natural numbers is 44400. 2. The sum of squares of first 20 natural numbers is 2870. Which of the above statements is/are correct?

Options

  1. A1 only
  2. B2 only
  3. CBoth 1 and 2
  4. DNeither 1 nor 2

Correct answer

B. 2 only

Step-by-step solution

1^3+2^3+3^3+ +n^3= ( n(n+1) 2 )^2 1^3+2^3+3^3+ .+20^3= ( 20.21 2 )^2=(10 21)^2=441001^2+2^2+3^3+ +n^2= 1 6 n(n+1)(2 n+1) 1^2+2^2+ +20^2= 1 6 20.21 .41=2870

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