6+12+24+..........+384= ?
Solution
Correct Answer: Option C
১ম পদ, a = 6 সাধারণ অনুপাত,
q=12/6 =2>1
ধরি, n তম পদ = 384
বা, aqn-1= 384
বা, 6(2)n-1= 384
বা, 2n-1= 64
বা, 2n-1=26
বা, n-1 = 6
..n=7 - সমষ্টি,
s = a.(qn-1)/q-1 = 6(27-1)/2-1 =6(128 - 1) = 6 x 127 = 762
Practice More Questions on Our App!
Download our app for free and access thousands of MCQ questions with detailed solutions