Fifty part-time students taking three courses or less were asked how many courses they were taking this term. The incomplete results are shown below: # of Courses Frequency Relative Frequency Cumulative Relative Frequency 1 30 0.6 2 15 3 What is the cumulative frequency for students taking 1, 2, or 3 courses? a) between 20.01% and 25% b) between 10.01% and 15% c) between 15.01% and 20% d) more than 25% e) less than 10%