गुणोत्तर श्रेणी \(4,12,36,\ldots\) में कितने पदों तक योग (484) होगा?
How many terms of the geometric progression \(4,12,36,\ldots\) have sum (484)?
Explanation opens after your attempt
B. (5)
Concept
(S_n=\frac{4\(3^n-1\)}{3-1}=2\(3^n-1\)), and (2\(3^n-1\)=484) gives (n=5). In exams, simplify the sum and identify the power.
Why this answer is correct
The correct answer is B. (5). (S_n=\frac{4\(3^n-1\)}{3-1}=2\(3^n-1\)), and (2\(3^n-1\)=484) gives (n=5). In exams, simplify the sum and identify the power.
Exam Tip
(S_n=\frac{4\(3^n-1\)}{3-1}=2\(3^n-1\)) और (2\(3^n-1\)=484) से (n=5) है। परीक्षा में योग को सरल करके घात पहचानें।
Login to save your score, XP, coins and progress.
