1 .trung binh cong cua hai phan so la 5/12 .neu tang phan so thu nhat gap 2 lan thi trung binh cong cua chung bang 2/3 .tim hai phan so do .
2.trung binh cong cua ba phan so la 13 /36 .neu tang phan so thu nhat gap 2 lan thi trung binh cong cua chung bang 19/36 ,cho biet phan so thu hai lon hon phan so thu ba 1 /12. tim ba phan so do .
trung binh cong cua 3 so la 20.neu gap so thu nhat len 2 lan thi trung binh cong cua chung la24.neu gap so thu hai len 3 lan thi trung binh cong cua chung la 32.tim so thu ba.
trung binh cong cua 3 so la so be nhat co 3 chu so khac nhau . biet so thu hai bang trung binh cong cua 2 so con lai . so thu 3 hojn so thu nhat la 14 . tim 3 so do.
cho 3 so co trung binh cong la 21.Tim so thu ba biet so thu ba gap 3 lan so thu hai,so thu hai gap 2 lan so thu nhat
cho 3 so co trung binh cong la 21 tim so thu ba biet so thu ba gap 3 lan .so thu hai so thu hai gap 2 lan so thu nhat
cho 3 so co trung binh cong la 21 tim so thu ba biet so thu 3 gap 3 lan so thu hai s thu hai gap 2 lan so thu nhat
trung binh cong cua so thu nhat va so thu 2 la 8.5 trung binh cong co so thu 2 va so thu 3 la 8.1 trung binh cong cua so thu nhat va so thu 3 la 7.35 tim so lon nhat , cac ban nho tim gium minh nhe!!
cho ba so co trung binh cong la 21.tim so thu ba biet so thu ba gap3 lan so thu hai,so thu hai gap 2 lan so thu nhat
Trung binh cong moi so la 67 , trong do so thu nhat gap doi so thu ba . Neu gap so thu nhat len 2 lan va cong voi so thu ba thi trung bing cong hai so do la 118 . Tim 3 so