Courtney receives a mailer to a local store. in the mailer, there are two coupons which cannot be combined. one coupon is for $20 off a purchase of $100 or more. the other coupon is for 15% off any purchase. if courtney wants to buy a $200 lawnmower, which coupon should she use? a) courtney should use the $20 off coupon. b) courtney should use the 15% off coupon. c) there is not enough information since the tax rate is not given. d) courtney will spend the same amount regardless of which coupon she uses.