NIMCET 2011 — Mathematics PYQ
NIMCET | Mathematics | 2011The sum of 112+122+⋯+302 is:
Choose the correct answer:
- A.
8070
- B.
9070
(Correct Answer) - C.
1080
- D.
9700
9070
Explanation
1. Recall the Formula:
The sum of squares of the first n natural numbers is given by:
2. Set up the Calculation:
The required sum can be calculated as the sum of squares up to 30 minus the sum of squares up to 10:
3. Calculate ∑k=130k2 (where n=30):
4. Calculate ∑k=110k2 (where n=10):
5. Find the final difference:
Conclusion:
The sum of the series is 9070.
The correct option is (b).
Explanation
1. Recall the Formula:
The sum of squares of the first n natural numbers is given by:
2. Set up the Calculation:
The required sum can be calculated as the sum of squares up to 30 minus the sum of squares up to 10:
3. Calculate ∑k=130k2 (where n=30):
4. Calculate ∑k=110k2 (where n=10):
5. Find the final difference:
Conclusion:
The sum of the series is 9070.
The correct option is (b).
