Sum of squares of first n natural numbers:
An³
Bn(n+1)(2n+1)/6
Cn(n+1)/2
Dn²(n+1)²/4
Answer & Solution
Correct answer: B. n(n+1)(2n+1)/6
Σk² from 1 to n = n(n+1)(2n+1)/6. For n=10: 10×11×21/6 = 2310/6 = 385. Standard formula. Also Σk³ = [n(n+1)/2]² = (Σk)².
Related questions
A CAT QA question reads: 'Anjali's salary increased by 20% in 2024. In 2025, the new salarA CAT taker has 4 TITA questions blank with 20 seconds left. The best move is:In the LAST 5 MINUTES of a CAT QA section, the recommended strategy is:A CAT QA word problem says 'the price was reduced from ₹100 to ₹85'. The percent change isA CAT TITA (Type-In-The-Answer) question has NO negative marking. The correct strategy is:CAT MCQ scoring is +3 for correct, −1 for wrong. The expected value of a pure random guessA CAT QA question asks: 'What is x if 5x − 7 = 38?' Options: x = 5, 7, 9, 11. The fastest In a CAT QA section, the recommended first action is to: