Percentage of
Percentage change
Ratio
GST
Rates
100
Find 28% of $600
28% / 100 = 0.28 (of means times) 0.28 x 600 = $168
100
If an ipod has a cost price of $230 and the shop wants to make a 20% profit, what should the selling price be?
100% + 20% = 120% / 100 = 1.2 230 x 1.2 = $276
100
If there are 28 students in a room and 2 teachers, what is the ratio of students:teachers?
14:1
100
A drill costs $120 ex. GST. What is the GST to pay?
GST = 12.5% / 100 = 0.125 0.125 x 120 = $15.00 to pay OR: $120 / 8 = $15.00 to pay
100

If John travels 180km in 2 hours, what was his average speed?

180/2 = 90km/h

200
What is 45% of $80?
45% / 100 = 0.45 0.45 x 80 = $36
200
A shirt is in sale at 35% off. If the retail price was $130, what is the sale price?
100% - 35% = 65% / 100 = 0.65 130 x 0.65 = 84.50
200

If Peta is making pasta with a ratio of cups of flour to egg that is 2:1, how much flour would she need to use 3 eggs?

2:1 = 6:3

So Peta would use 6 cups of flour


200
If a laptop costs $890 ex. GST what is the total price including GST?
100% + 12.5% = 112.5% / 100 = 1.125 890 x 1.125 = $1001.25 OR: $890 /8 x 9 = $1001.25
200

If Milla makes 27 coffees in 1.5 hours, what is the average rate she is making coffee per hour?

27/1.5 = 18 coffees /hour

300
A surfboard shop offers 15% discount. If a board retails for $650, by how much will it be reduced?
15% / 100 = 0.15 0.15 x 650 = $97.50
300
A shop increases the price of a $28 flash drive by 10%. How much does the price increase by?
10% / 100 = 0.10 0.10 x 28 = $2.80 increase
300

If the ratio of teachers:students on an excursion needs to be 1:10 and 120 students are going on the excursion, what is the minimum number of teachers that need to go?

1:10 = 12:120 so they need to send at least 12 teachers

300
A skateboard costs $126 including GST. What is the price exclusive of GST?
100% + 12.5% = 112.5% / 100 = 1.125 126 / 1.125 = $112.00 OR: $126 / 9 x 8 = $112.00
300

If Steve drives 360 km in 4 hours, how far would you expect him to drive in 6 hours?

360km/4h 

6/4 = 1.5

360km/4h x 1.5 = 540km/6h

540km in 6h

400
The number of logs a driver can load in an hour is 75. If this is 12% of the total logs loaded, what is the total number of logs loaded in that hour?
12% / 100 = 0.12 75 / 0.12 = 625 logs
400
If a jacket is on sale for $123 and has 40% off, what was the original price?
100% - 40% = 60% / 100 = 0.6 123 / 0.6 = $205
400

Divide $600 in the ratio 7:5

$350:$250

400
If someone is paying $360 rent per week inclusive of GST, how much GST do they pay in a year?
360 / 1.125 = $320 ex. GST so GST is $40 x 52 weeks = $2080 OR: 360 / 9 = $40 x 52 weeks = $2080
400

Lilly can choose between fresh blueberries which are $4.00 for 200g or frozen blueberries which are $6.50 for 400g. Which one is the best buy?

Fresh: $4/200g = $8/400g

Frozen: $6.50/400g

Frozen is the better deal.

500
Tom buys a 2nd hand car. The asking price is $1500. Tom offers 20% less and the seller suggests 10% more than Tom's offer. What price does the seller now want?
100% - 20% = 80% / 100 = 0.8 1500 x 0.8 = $1200 100% + 10% = 110% / 100 = 1.1 1200 x 1.1 = $1320
500
Petrol went up 12% yesterday. If the new price is $1.68 per litre, what was the original price?
100% + 12% = 112% / 100 = 1.12 1.68 / 1.12 = $1.50
500

Paora and Stuart bought a $6 lotto ticket together which won $3000. If Paora contributed $4 and Stuart contributed $2, how should the prize be divided?

Paora:Stuart = 4:2
4 + 2 = 6, 3000 / 6 = $500

Paora gets 4 x $500 = $2000 

Stuart gets 2 x $500 = $1000

500
A shop accidentally charges GST twice on a pair of jeans. If the price ex. GST was $80, what price did the shop charge?
100% + 12.5% = 112.5% / 100 = 1.125 80 x 1.125 x 1.125 = $101.25
500

Ben can choose between a 3-pack of socks for $7.00 or a 5-pack for $10. Which one is the best buy?

$7.00/3 pairs = $2.33

$10/5 pairs = $2.00

5 Pairs is a better deal

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