5 votes 5 votes Insert seven numbers between $2$ and $34$, such that the resulting sequence including $2$ and $34$ is an arithmetic progression. The sum of these inserted seven numbers is ______. $120$ $124$ $126$ $130$ Quantitative Aptitude gate2020-ce-1 quantitative-aptitude arithmetic-series + – go_editor asked Feb 27, 2020 • recategorized Feb 13, 2021 by Lakshman Bhaiya go_editor 2.1k views answer comment Share Follow Migrated from GO Civil 3 years ago by Arjun See all 0 reply Please log in or register to add a comment.
0 votes 0 votes a = 2 and l = 34 A total of seven numbers are inserted between a and l so the total number of terms in A.P. will become 9. Sum of nine numbers = n/2(a+l) =9/2(2+34) =162 Sum of inserted numbers = sum of nine numbers – (a+l) = 162 – 36 = 126 Therefore the correct answer is (C) Teja25 answered Jul 12, 2023 Teja25 comment Share Follow See all 0 reply Please log in or register to add a comment.
0 votes 0 votes The shortcut method for above questions is S= Sum N = No. of terms a = First term l = Last term S = (N*(a+l))/2 S = (7*(2+34))/2 S = (7*(36))/2 S = 7*18 S = 126 Hence the answer is Option C. 126 SurajS27 answered Jul 22, 2023 SurajS27 comment Share Follow See all 0 reply Please log in or register to add a comment.
0 votes 0 votes Total number of terms including 2,34 = 9 WKT n/2(first term+last term)=> 9/2(2+34)=> 162 This 162 sum contains 2,34 also. They asked for only sum of seven inserted numbers So: 162-(2+34)=126 Option C is answer Krishna Reddy kyp answered Mar 14 Krishna Reddy kyp comment Share Follow See all 0 reply Please log in or register to add a comment.