In a GP if a=2 and r=3 then what is the sum of first 4 terms?
GP में a=2 r=3 है तो पहले 4 पदों का योग कितना होगा?
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Correct Answer
C. 80
ExplanationStep 1: Use GP sum formula Sn=a(r^n-1)/(r-1). Step 2: S4=2(3^4-1)/(3-1)=2×80/2=80. Step 3: When r is greater than 1 use r^n-1.
Step 1: GP sum formula Sn=a(r^n-1)/(r-1) लगाएं। Step 2: S4=2(3^4-1)/(3-1)=2×80/2=80। Step 3: r greater than 1 हो तो r^n-1 use करें।