A furniture store was having Mid Year discount of 10% off its usual price. The GST is at 6%. Yen used her credit card to purchase a sofa bed and Japheth used cash to pay for a similar sofa bed.

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

New sofa bed Usual Price: $1600

Further Discount: Pay by credit card: 10% off discounted price before GST! Pay by cash: $100 off discounted price before GST!

	Credit Card	Cash
Usual Price	$1600	$1600
Less 10% discount	- $160.00	- $160.00
Price after 10% discount	$1440.00	$1440.00
Less further discount	- $144.00	- $100
Price after further discount	$1296.00	$1340.00
Price after GST of 6%	$1373.76	$1420.40

(a)
New selling price after 10% discount
= 100% - 10%
= 90%

Price of the sofa bed after Mid Year discount
= 90% x 1600
= ⁹⁰₁₀₀ x 1600
= $1440.00

New selling price after 10% further discount
= 100% - 10%
= 90%

Price of the sofa bed after credit card discount
= 90% x 1440.00
= ⁹⁰₁₀₀ x 1440.00
= $1296.00

Price to pay after including GST
= 100% + 6%
= 106%

Price of the sofa bed after GST
= 106% x 1296.00 
= ¹⁰⁶₁₀₀ x 1296.00 
≈ $1373.76 (Round off to nearest cent)

(b)
Price of the sofa bed after cash discount
= 1440.00 - 100
= $1340.00

Price of the sofa bed after GST
= 106% x 1340.00 
= ¹⁰⁶₁₀₀ x 1340.00 
≈ $1420.40 (Round off to nearest ten cent)

Answer(s): (a) $1373.76; (b) $1420.40