There's a 60 cent difference in the base price, and the price of toppings is a 5 cent difference, so it would take 60/5 or 12 toppings to make up the difference. r, you can make a chart. Or you can do algebra and solve an equation:
6.75 + .75 x = 6.15 + .8x where x is the number of toppings. Subtract 6.15 from both sides.