9/15 10/15 then make the denominators smaller
18/30 20/30 make them smaller again
36/60 40/60 I will start here, and show you how to get it:
37/60, 38/60, 39/60 and if you simplify:
37/60, 19/30, 13/20 are between 3/5 and 2/3
If you need more than that, you would need to continue to make the denominators smaller.