16/6 : 1 11/21 - 9/16 · (3 - 1 22/27) = 5/6
1) 16/7 : 1 11/21 = 16/7 : 32/21 = 16/7 · 21/32 = (1·3)/(1·2) = 3/2
2) 3 - 1 22/27 = 2 27/27 - 1 22/27 = 1 5/27
3) 9/16 · 1 5/27 = 9/16 · 32/27 = (1·2)/(1·3) = 2/3
4) 3/2 - 2/3 = 9/6 - 4/6 = 5/6
Ответ: 5/6.