4/5 = 0.8
8/25 = 0.32
1/4 = 0.25
3/50 = 0.06
17/20 = 0.85

Итак, в виде десятичной дроби:

4/5 = 0.8
8/25 = 0.32
1/4 = 0.25
3/50 = 0.06
17/20 = 0.85