Seven units long. The distance between 2 sides, in this example is 6, and -1. The distance between 6 and -1 is 7, so when you add units, you get 7 units.
This means that the bicycle was discounted in total by 60%, so $315 is 40% of the original price to get 40% to 100% youd multiply it by 2.5 so so the same to the price 315 x 2.5= 787.5