Răspuns :
S= 1+3+5+...+101
S=101+99+97+...+1
___________________
2S=102+102+102+...+102
S=102:2x51
S=51x51
S=2601
S=101+99+97+...+1
___________________
2S=102+102+102+...+102
S=102:2x51
S=51x51
S=2601