SSC CGL 2024 PYQ — Question 60

SSC CGL - 12 Sep 2024 - Shift 2 • Quantitative Aptitude • Q60

The average of the squares of the first 46 natural numbers is:

Show answer & explanation

Correct answer: B

Explanation

The correct answer is option 2 i.e. 728.5.

The sum of the squares of the first n natural numbers = n(n+1)(2n+1)6{n(n + 1)(2n + 1)\over 6}

Sum of numbers = Average of numbers × Number of numbers

According to the given question,

Sum of first 46 natural numbers = 46(46+1)(2(46)+1)6{46(46 + 1)(2(46) + 1)\over 6}

⇒ 46×47×936{46 \times 47 \times 93\over 6} 

⇒ 23 × 47 ×31 = 33511

Average = 335114633511 \over 46

⇒ 728.5

Hence the average of the squares of the first 46 natural numbers is 728.5.