Same chapter3 marksDifficulty: Medium
The 2nd term of a geometric progression is 3 and the 5th term is 81. Find the first term and the common ratio.
Arithmetic and Geometric Progression
1 markDifficulty: Medium
The sum of the first n terms of an arithmetic progression with first term a and common difference d is:
- an(a + d)
- bn/2 × [2a + (n − 1)d]
- ca + (n − 1)d
- dn/2 × [a + (n − 1)d]
Original Khojo Papers practice question — not from a past board paper.
Answer
n/2 × [2a + (n − 1)d]
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
Option (c) is the nth term, not the sum.
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