*Đây là môn toán tiếng anh :D
5, Minh wants to invite 7 friends A,B,C,D,E,F and G to his dinner, but his table can be only for 4 people. Not counting Minh, there are only 3 friends that can be invited each time. Therefore, Minh decides to invite 3 friends to each dinner, but also wants that every two friends have dinner with him at least once. At least how many dinners should Minh arrange?
(A) 5
(B) 6
(C) 7
(D) 8
(E) 9
Loga
Sinh Học lớp 12
