Ответ:

  1. 0,25 = 25/100 = 1/4.
  2. 1,38 = 138/100 = 69/50 = 1 19/50.
  3. 3/4 = 75/100 = 0,75.
  4. 2 9/20 = 2 + 45/100 = 2,45.