The total cost of a tradesperson's invoice, including 10% GST, is $462.
What was the cost of the job before GST was added?
- $415.80
- $420.00
- $462.00
- $508.20
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The total cost of a tradesperson's invoice, including 10% GST, is $462.
What was the cost of the job before GST was added?
\(B\)
\(\text{GST-inclusive price is 110\% of original cost}\)
\(\text{Original cost}=\dfrac{462}{1.1}=\$420.00\)
\(\Rightarrow B\)
A mechanic in Parramatta charges $720 for a car service, plus 10% GST.
What is the total cost of the service, including GST?
\(D\)
\(\text{Total cost}=720\times 1.1=\$792\)
\(\Rightarrow D\)
Jacinta buys several items at the supermarket. The docket for her purchases is shown below.
What is the amount of GST included in the total?
\(A\)
\(\text{Total price of taxable items}\ +\ 10\%\ \text{ GST}\ =1.29+7.23+4.13=$12.65\)
| \(\therefore\ 110\%\ \text{of original price}\) | \(=$12.65\) |
| \(\therefore\ \text{GST}\) | \(=$12.65\times\dfrac{100}{110}=$1.15\) |
\(\Rightarrow A\)
A karate school runs a holiday program and charges $150 per student.
The costs of running the program are:
Karate instructor: $110 per hour
Hall hire: $52 per hour plus 10% GST.
The program runs for two hours a day for five days.
What profit does the karate school make if 20 students pay for the program? (3 marks)
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`$1328`
`text(Revenue) = 20 xx 150 = $3000`
| `text(Cost per hour)` | `= 110+(52 xx 1.1)` |
| `= 110+57.20` | |
| `= $167.20` |
| `text(Total cost)` | `= 2 xx 5 xx 167.20` |
| `= $1672` |
| `:.\ text(Profit)` | `= 3000-1672` |
| `= $1328` |
The price of a book is $33.00, which includes 10% GST.
What is the amount of GST included in this price?
`B`
`text(Book costs $33.00 incl. GST)`
`text(Let)\ C = text(original cost)`
| `C + 10\% × C` | `= 33` |
| `1.1C` | `= 33` |
| `C` | `= 30` |
| `:.\text(GST)` | `= 33.00-30.00` |
| `= $3.00` |
`=> B`
The cost of a plumbing job is $500 plus 10% GST.
What is the total cost of the job, including GST?
\(D\)
| \(\text{Total Cost}\) | \(=500+0.10\times 500\) |
| \(=500+50=$550\) |
\(\Rightarrow D\)
An item was purchased for a price of $880, including 10% GST.
What is the amount of GST included in the price?
\(C\)
\(\text{Let}\ C =\text{Original cost}\)
| \(C+0.1 \times C\) | \(=880\) | |
| \(1.1C\) | \(=880\) | |
| \(C\) | \(=\dfrac{880}{1.1}=$800\) |
\(\therefore \text{GST}=800\times 0.1=$80\)
\(\Rightarrow C\)
A dance school runs a holiday program and charges $150 per student.
The costs of running the program are:
Dance teacher: $110 per hour
Room hire: $52 per hour plus 10% GST.
The program goes for two hours a day for five days.
What profit does the dance school make if 20 students pay for the program? (3 marks)
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`$1328`
`text(Revenue) = 20 xx 150 = $3000`
| `text(Cost per hour)` | `= 110 + (52 + \text{GST})` |
| `= 110 + 52 xx 1.1= $167.20` |
`text(Total cost)= 2 xx 5 xx 167.20= $1672`
`:.\ text(Profit)= 3000-1672= $1328`
Part of a supermarket receipt is shown.
Determine the missing values, `A` and `B`, to complete the receipt. (2 marks)
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`$9.00`
`text(Chocolate is the only item where GST applies.)`
`text(GST on chocolate = 0.70)`
`=> text(C)text(ost of chocolate) = $7.00`
`:. A = 7.00 + 0.70 = $7.70`
| `:. B` | `= 36.25 – (7.70 + 5.00 + 8.50 + 3.20 + 2.85)` |
| `= $9.00` |
Alex is buying a used car which has a sale price of $13 380. In addition to the sale price there are the following costs:
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The cost of comprehensive insurance is calculated using the following:

Find the total amount that Alex will need to pay for comprehensive insurance. (3 marks)
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What extra cover is provided by the comprehensive car insurance? (1 mark)
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a. `$402`
b. `$985.74`
c. `text(Comprehensive insurance also covers Alex for damage to his own car.)`
a. `($13\ 380)/100 = 133.8`
`text(Stamp duty)= 134 xx $3= $402`
b. `text(Base rate)= $845`
`text(FSL) =\ text(1%) xx 845 = $8.45`
| `text(Stamp)` | `=\ text(5.5%) xx(845 + 8.45)` |
| `= 46.9397…` | |
| `= $46.94\ text{(nearest cent)}` |
`text(GST)= 10 text(%) xx(845 + 8.45)= 85.345= $85.35`
| `:.\ text(Total cost)` | `= 845 + 8.45 + 46.94 + 85.35` |
| `= $985.74` |
c. `text(Comprehensive insurance covers Alex for damage done)`
`text{to his own car as well.}`
A camera costs $449, including 12% GST.
What is the price of the camera without GST, correct to the nearest dollar?
`B`
`text(Let)\ C\ text(= cost of camera ex-GST)`
| `C + text(12%)C` | `= $449` |
| `1.12C` | `= 449` |
| `:. C` | `= 449/1.12` |
| `= $400.89…` |
`⇒ B`
Rita purchased a camera for $880 while on holidays in Australia. This price included 10% GST. When she left Australia she received a refund of the GST.
What was Rita’s refund?
`A`
`text(Let)\ C = text(cost before GST)`
| `880` | `= C + text(10%) C` |
| `1.1C` | `= 880` |
| `C` | `= $800` |
`:.\ text(GST)=10 text(%) xx 800= $80`
`=> A`
The price of a CD is $22.00, which includes 10% GST.
What is the amount of GST included in this price?
`A`
`text(CD costs $22.00 incl. GST`
`text(Let)\ C = text(original cost)`
| `C + text(10%) xx C` | `= 22` |
| `1.1C` | `= 22` |
| `C` | `= 20` |
`:.\ text(GST)= 22.00-20.00= $2.00`
`=> A`
A new phone was purchase for $725 which included 10% GST.
What was the price of the phone without GST, correct to the nearest cent?
`D`
| `text(Phone price)\ +\ text(10% GST)` | `=725` |
| `text(110%)\ xx\ text(Phone price)` | `=725` |
| `:.\ text(Phone price)` | `=725/1.1` |
| `=$659.09` |
`=> D`