27 61/48
7+9+11=27
общее число 48
а с верху 3×4+3×7+4×7=61
7 3/8 + 9 7/16 + 11 7/12 =
= (7 + 9 + 11) + (3/8 + 7/16 + 7/12) =
= 27 + (6•3/48 + 7•3/48 + 7•4/48) =
= 27 + (18/48 + 21/48 + 28/48) =
= 27 + 67/48 = 27 + 1 19/48 = 28 19/48
ответ: 28 целых 19/48
