A pair of shoes with a manufacturer's price of $80 is marked up 115% and then sold to a customer at 65% off the mark up price. If a 10% tax is added to this cost, then the total price the customer paid for the shoes, in dollars, was....

Question

I know the answer but don't understand it at all

Answer 1

80 * 2.15 * 0.65 * 1.10 = 122.98

note that a 15% markup multiplies the price by 1.15 (the original amount + 15% of that amount: 1 + 0.15)
so, a 115% markup multiplies it by 2.15 (1 + 1.15)

Answer 2

oops. I didn't see the 65% off. That means they paid only 35%. So the real calculation is
80 * 2.15 * 0.35 * 1.10 = 66.22

Answer 3

80 * (1 + 1.15) * (1 - .65) * (1 + .10) = ?

price * mark up * discount * tax = total price paid