Question

Emily has a coupon for 10%off of her purchase at the store. she finds a backpack that she likes on the discount rack. it’s original price is $60 but everything on the rack comes with the 30% discount. Emily says 10% and 40% make 50% so it will cost $30 is Emily correct explain what price will Emily pay for the backpack

Answer 1

It is true that 20% and 30% make 50%. But in the context of sale prices it is essential to keep track of the wholes to which these percents apply. For the backpack, the 30% discount applies to the original $60 price: 30% of $60 is 0.3×60=18 making the discount on the backback $18. So after using the coupon, the backpack price becomes $42. Emily's additional 20% coupon applies not to the original backpack price but to the discounted price of $42: 20% of $42 is $8.40. Emily would need to save an additional $12 off the $42 price in order to buy the backpack for $30 so her calculations are not correct.

As seen in part (a), Emily's coupon lowers the discount rack price by $8.40 so she will pay

42−8.40=33.60

or $33.60.

Explanation: