A boy starts adding consecutive natural no.s starting from 1. After some time, he reaches a total sum of 1000 when he realises that he has double counted a number. Find the number double counted.
1000 x 2 = 2000
Sqrt(2000) =~45
[45 x 46] / 2 =1035
1035 - 1000 =35 - The number that was counted twice
+36916 \(\sum_{0}^{44}\) n =990
\(\sum_{0}^{45}\) n = 1035 HE MUST HAVE COUNTED '10' TWICE !
