Răspunsuri

2014-10-06T20:51:39+03:00
3 + 7 + 11 + 15 +  . . . + 2002
s=3+7+11+15+...+2002
s=2002+.........+7+3
-----------------------------
2s=2005+2005+...+2005  de 500 ori
s=2005*500:2
s=501250