1)3/8*4/5:9/10=3/10* 10/9 = 3/9 = 1/3
2) 6/7:3/5*1 2/5 = 6/7*5/3 *7/5 = 2
3)2 2/11*1 3/8:3/4 = 24/11*11/8 * 4/3 = 4
4)11/23*3 2/7:5 1/2 = 11/23*23/7 : 11/2 = 11/23*23/7*2/11=2/7
5)3/5*(2 2/3:3 1/5)=3/5*(8/3:16/5)=3/5*8/3*5/16=1/2
6)1 1/8*(9 1/3:1 3/4)= 9/8*(28/3:7/4)= 9/8*28/3*4/7= 6