So, he runs 1.5 then adds 0.5 every day, 1.5 (1.5+0.5)+1.5=x (2.0+0.5)+x=z 2.5+0.5+z=y etc. Why, they want to know the total distance he runs, so thats why you add x,y,z to the end, and you add 2.0+0.5 because he adds 0.5 every dat Plus the other day's miles jogged
