First we need to calculate the selling price after 50% increase selling price = original cost + increase selling price = 100% original cost + 50% original cost selling price = 150% original cost selling price = 1.5 × original cost selling price = 1.5 × 30 selling price = 45 The selling price after getting a markup is $45
Second, we need to calculate the sale price after markdown 50% Right now, we use $45 as the original price not $30 to count the sale price sale price = original price - markdown sale price = 45 - 50% × 45 sale price = 45 - 0.5 × 45 sale price = 45 - 22.5 sale price = 22.5 The sale price is not $30