Damaged items are marked down 20% to 40%. A newspaper coupon entitles the coupon holder additional 15% markdown. What is the lowest price of a damaged item that was originally marked $36?
What I did was 0.85(0.6(36) ) = 18.36
But the explaination says total discount is 40+15 == 55%
so 0.45(36) = 16.20
Can we add successive discounts like this to get the lowest price? How is this different from successive increases or decreases which we should not add together?