Question
A student read common difference of an A. P. as -2 instead of 2 and got the sum of first 5 terms as -5 . Actual sum of first five terms is
A student read common difference of an A. P. as -2 instead of 2 and got the sum of first 5 terms as -5 . Actual sum of first five terms is
D. 35
5 2 \ 2 a +4(-2)\ =-5 2 a =6 Actual sum = 5 2 \ 6+4(2)\ =35
Related: Mathematics — Sequences and Series · All PYQ Banks