The computer only understands 0 and 1. It understands 0 as On and 1 as Off. It is the only things that they can interpret in which they use it to identify different things like images, sounds, the alphabets and so many other things.
30% off 25: multiply 25 by .30 to find 30%: 7.5. Now subtract that from the sales price: 25-7.5=17.5 Do the same for store B: .40•30=12. 30-12=18. So store A is better by $.50 :) hope this helps :)
