A furniture store was having Grand Opening discount of 30% off its usual price. The GST is at 4%. Gwen used her credit card to purchase a kitchen table and Oliver used cash to pay for a similar kitchen table.

1. How much did Gwen pay in the end after GST? Round off your answer to the nearest cent.
2. How much did Oliver pay in the end after GST? Round off your answer to the nearest ten cent.

New kitchen table Usual Price: $700

Further Discount: Pay by credit card: 15% off discounted price before GST! Pay by cash: $30 off discounted price before GST!

	Credit Card	Cash
Usual Price	$700	$700
Less 30% discount	- $210.00	- $210.00
Price after 30% discount	$490.00	$490.00
Less further discount	- $73.50	- $30
Price after further discount	$416.50	$460.00
Price after GST of 4%	$433.16	$478.40

(a)
New selling price after 30% discount
= 100% - 30%
= 70%

Price of the kitchen table after Grand Opening discount
= 70% x 700
= ⁸⁵₁₀₀ x 700
= $490.00

New selling price after 15% further discount
= 100% - 15%
= 85%

Price of the kitchen table after credit card discount
= 85% x 490.00
= ⁸⁵₁₀₀ x 490.00
= $416.50

Price to pay after including GST
= 100% + 4%
= 104%

Price of the kitchen table after GST
= 104% x 416.50 
= ¹⁰⁴₁₀₀ x 416.50 
≈ $433.16 (Round off to nearest cent)

(b)
Price of the kitchen table after cash discount
= 490.00 - 30
= $460.00

Price of the kitchen table after GST
= 104% x 460.00 
= ¹⁰⁴₁₀₀ x 460.00 
≈ $478.40 (Round off to nearest ten cent)

Answer(s): (a) $433.16; (b) $478.40