2:1/7,4:2/3,3:3/5,1:2/7,1:1/4.

2 : 1/7 = 14 
4 : 2/3 = 12/2 = 6 
3 : 3/5 =15/3 = 5 
1 : 2/7 = 7/2 = 3,5 
1 : 1/4 = 4/1 = 4 

а) 2:1/7=2*7/1=14
б) 4:2/3=4*3/2=2*3/1=6
в) 3:3/5=3*5/3=1*5/1=5
г) 1:2/7=1*7/2=7/2=3 целых 1/2=3,5
д) 1:1/4=1*4/1=4