Percentage change

Question 2

Which is the better buy? Supersafe is offering a 15% discount if you buy three boxes of Brekkygrain which cost $6.53 each. Barnway is offering a 12% discount if you buy three boxes of Brekkygrain which cost $6.25 each. Round your answers to the nearest cent.

Solution

A discount is a percentage decrease.

Supersafe

1 − 15% = 1 − \(\dfrac{15}{100}\)	= 1 − 0.15 = 0.85
(1 − 15%) × 6.53 × 3	= 0.85 × 6.53 × 3
	= 16.6515.

Barnway

1 − 12% = 1 − \(\dfrac{12}{100}\)	= 1 − 0.12 = 0.88
(1 − 12%) × 6.5 × 3	= 0.88 × 6.5 × 3
	= 16.5.

Barnway has the better deal as you pay $16.50 compared with $16.65 at Supersafe.

Method 3

Question 3