1/9 + 2/9 + 4/9 = (7/9); 2/9 + 5/9 = (7/9) ; 1/10 + 3/10 = (2/5) ; 175175/275275=(7/11)

12/ - DE THI VA DAP AN VIOLYMPIC LOP4V2630
DE THI VA DAP AN VIOLYMPIC LOP4V2630

12/ 1/9 + 2/9 + 4/9 = (7/9); 2/9 + 5/9 = (7/9) ; 1/10 + 3/10 = (2/5) ; 175175/275275=

(7/11)