Two-fifths of one less than a number is less than three-fifths of one more than that number

What could explain what happened when the time was equal to 120 minutes

Researchers were interested in whether relaxation training decreases the number of headaches a person experiences. they randomly assigned 20 participants to a control group or a relaxation training group and noted the change in number of headaches each group reported from the week before training to the week after training. which statistical analysis should be performed to answer the researchers' question?

How to simply and write the answer n a whole number