1) 1 3/4 * 5/16 * 2 2/3 * 6 6/7=7/4 * 5/16 * 8/3 * 48/7=(7*5*4*2*16*3) / (4*16*3*7)=5*2=10
2) 1 7/9 : 1 1/3 : 2 : 1 3/5=16/9 : 4/3 : 2 : 8/5=16/9 * 3/4 * 1/2 * 5/8=
(8*2*3*5) / (3*3*4*2*8)=5/12
3) 7 1/5 * 2 : 1 1/7 * 1 2/3=36/5 * 2 : 8/7 * 5/3=36/5 * 2 * 7/8 * 5/3=
(4*3*3*2*7*5) / (5*4*2*3)=21