Phuong phap 1:choi kang co dinh:1,2,3,4,5,6,7,8 Phuong phap 2: lay tat ca cac so o giai 7 hoac giai 6 lam kang 3d.giai nao chay choi giai do.hoac gom ca 2 lay du 7kang
Tong thi loai o giai dac biet.vi du de ve 47 thi loai tong 4 tong 7.nay de ve 65 thi loai tong 5 tong 6 cho ngay mai
6 cham 8 tong thuong ep ra 67so.cuoc 65so 2d con 2so ghep 10kang vao cuoc 3d.ko thi tu loai ra lay 65s thoi
Phuong phap 2: lay tat ca cac so o giai 7 hoac giai 6 lam kang 3d.giai nao chay choi giai do.hoac gom ca 2 lay du 7kang