-
The sum (5³ + 6³ + .... 10³) is equal to :
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- 2295
- 2425
- 2495
- 2925
- 2295
Correct Option: D
According to question ,
Sum = 5³ + 6³ + .... 10³
Sum = 125 + 216 + 343 + 512 + 729 + 1000 = 2925
Second method to solve this question :
Sn = (5³ + 6³ + ............ 10³)
Sn = (1³ + 2³ + 3³ + 4³ + 5³ +... 10³) – (1³ + 2³ + 3³ + 4³)
| Sn = |  |  | ² | - (1 + 8 + 27 + 64) | |
| 2 |
| Sn = | | | ² | - 100 | |
| 2 |
Sn = (55)² – 100 = 3025 – 100 = 2925
