Question

cat face 1+2+3....+48+49+50

Answer 1

Formula lui Gaus, 50×51:2=2550:2=1275

Answer 2

$1+2+3+...+n = \frac{n*(n+1)}{2} \\ =\ \textgreater \ 1+2+3+...+49+50 = \frac{50*51}{2} = \frac{2550}{2} = 1275.$