Question

A) 1+2+3+...+60
B)1+2+3+...+73
C)1+2+3+...+120
D)1+2+3+...155
Prin suma lui Gauss

Answer 1

suma lui gauss e așa : n (n+1) : 2
a) 60 *61 :2 = 1830
b) 73*74 :2 = 2701
c) 120*121 ÷ 2 = 7260
d) 155* 156:2 = 12090