what is 1+2+3+4+5+6+7+8+...+998+999+1000
i got 500500 am I right
Sum of first n psitive integers = n ( n + 1) / 2
So
1000 (1001) / 2 =
500 * 1001
500500 !!!!
Correct !!!
thx for the help
+428 
