Same chapter3 marksDifficulty: Medium
The third term of a geometric progression is 12 and the sixth term is 96. Find the first term and the common ratio.
Sequence and Series
3 marksDifficulty: Medium
Find the sum of the first n natural numbers, their squares and their cubes.
Original Khojo Papers practice question — not from a past board paper.
Answer
n(n + 1)/2, n(n + 1)(2n + 1)/6 and [n(n + 1)/2]2 respectively.
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
The sum of the cubes is the square of the sum, a result worth remembering.
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