Percentage change If a quantity goes through a change (increase or a decrease), we can work out the % change E.g. I bought a second hand Toyota Corolla liftback for $6500. 3 years later I sold it for $5000. Did I make a loss or a profit? What was the percentage loss?

Cost Price, Selling Price, Profit and Loss. E.g. Rhonda bought a parachute for $90. She sold it for $320. What was her profit? Express this profit as a % of the cost. 320 – 90 = $230 = Profit %Profit = = 256% E.g. Dino’s Dogfood Co. bought a bulk amount of dog biscuits for $885. They repackaged the biscuits, resulting in 60 packets in total and sold them for $13.50 a packet. Did they make a profit or a loss? Express this as a % of the cost price.

$13.50 × 60 = $810 = SP SP – CP = 810 – 885 = - $75 which means a loss of $75 They experienced a 8.5% loss.