Question

1+2+3...+200 rezolvarea

Answer 1

$Se \ foloseste \ formula \ : \\ \frac{n(n+1)}{2}= \ unde \ n \ este \ ultimul \ numar \ din \ sir \ (200) \\ \\ \frac{200(200+1)}{2} = \frac{200*201}{2} = 100*201=\boxed{20.100 \ raspuns \ final}$