What is the slope of the line

If an athlete can bike 6 miles in 25 minutes, how many miles will he bike in an hour and half if he continues to bike at the same rate?

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?

Having a hard time understanding this question (see attachment).