2022 · Q26
Which one of the following is the difference of the sum of cubes of first ten natural numbers and the sum of squares of first ten natural numbers?
general-mental-abilityquantitative-aptitude
- A2400
- B2640
- C2880
- D2000
Explanation
The sum of cubes of the first n natural numbers is [n(n+1)/2]^2 and the sum of squares is n(n+1)(2n+1)/6. For n = 10: sum of cubes = (10×11/2)^2 = 55^2 = 3025, and sum of squares = (10×11×21)/6 = 385. The difference is 3025 − 385 = 2640. Hence option B.