Plz help and show work plz

Aflute is on sale for 20% off. including the discount and 8% tax, the sales price is $216.

With number 11 ( show how you got the answer)

Traffic on saturday, it took ms. torres 24 minutes to drive 20 miles from her home to her office. during friday's rush hour, it took 75 minutes to drive the same distance. a. what was ms. torres's average speed in miles per hour on saturday? b. what was her average speed in miles per hour on friday?