(1 9/16 × 3 1/5 + 6 2/3 - 9 : 2 2/5) : (17 7/12 - 6 1/3)

1) $1 \frac{9}{16}*3 \frac{1}{5} = \frac{25*16}{16*5}= 5$
2) $9:2 \frac{2}{5}= 9:2,4=3,75$
3) 5+ $6 \frac{2}{3}$ = $11 \frac{2}{3}$
4) $11 \frac{2}{3}- 3,75= 11\frac{2}{3}-3 \frac{3}{4}= \frac{35}{3}- \frac{15}{4}= \frac{140-45}{12} = \frac{95}{12} = 7 \frac{11}{12}$
5) $17 \frac{7}{12}- 6 \frac{1}{3}= \frac{211-76}{12} = \frac{135}{12} = \frac{45}{4} = 11 \frac{1}{4}$
6) $7 \frac{11}{12}:11 \frac{1}{4}= \frac{95*4}{12*45} = \frac{19*1}{3*9}= \frac{19}{27}$
Ответ: $\frac{19}{27}$