1 1 vote Quantitative Aptitude sequence-series + – Parshu gate 2.4k views answer comment Share Follow Print 0 reply Please log in or register to add a comment.
Best answer 2 2 votes let S= 1/2 + 3/4 + 5/8 + 7/16 ... ∝ 2S = 1 + 3/2 + 5/4 + 7/8 ...∝ 2S - S = S = 1 + (3/2 - 1/2) + (5/4 - 3/4) + (7/8 - 5/8) ...∝ Leaving the 1st term of 2s , we subtract (2nd term of 2S- 1st term of S) , (3rd term of 2S - 2nd term of S ) and so on Hence S= 1 + 1+ (1/2 + 1/4 + 1/8 ...∝) Leaving the 1st term i.e. 2 (1+1) , the remaining terms are in infinite G.P. upto ∝ with r = 1/2, Summation of terms in inifinte GP = a/(1-r) where a is 1st term S = 2 + ((1/2) / (1-(1/2))) = 2 + 1 = 3 Sayan Bose answered Nov 6, 2017 • selected Nov 6, 2017 by Parshu gate Sayan Bose comment Share Follow See 1 comment 1 1 comment reply Parshu gate commented Nov 6, 2017 reply Follow flag Thanks bro . perfect explanation :) 1 1 replyShare Please log in or register to add a comment.
