Am nevoie de un răspuns la ex 10 URGENT!

Răspuns:
1+2+3+...+100=[100·(100+1)]/2=100·101:2=5050
2+4+6+...+200=2(1+2+3+...+100)=2·5050=10100
(5050/10100)⁽⁵⁰⁵⁰=1/2