Find the product for 56.44

Adepartment store purchases screen-printed t-shirts at a cost of $5 per shirt. they mark up the price 150% (making the selling price 250% of the store's purchase price) and put them on the sales floor. every month that a t-shirt doesn't sell, the store reduces the selling price by 25%.

The graph shows the distance kerri drives on a trip. what is kerri's speed . a. 25 b.75 c.60 d.50

Could somebody me with this radical simplification?