year 8 maths

Semester review 1 343
9 a Increase $560 by 25% .
b Decrease $980 by 12% .
c Increase $1 by 8% and then decrease the result by 8% .
10 A $348 dress sells for $261 . This represents a saving of x% . What is the value of x ?
11 Complete the table of pre- and post-GST prices; remember in Australia the GST is 10% .
Pre-GST GST Post-GST
$550.00
$7.00
$47.50
Extended-response question
$962.50
A laptop decreases in value by 15% a year.
a Find the value of a $2099 laptop at the end of:
i 1 year ii 2 years iii 3 years
b After how many years is the laptop worth less than $800 ?
c Is the laptop ever going to have a value of zero dollars? Explain.
Chapter 5: Ratios and rates
Multiple-choice questions
1 The ratio of the length to the breadth of this rectangle is:
A 12 : 80 B 3 : 20 C 3 : 2
D 20 : 3 E 2 : 3
80 cm
3
2 Simplify the ratio 500 cm to
4 km .
1.2 m
A 2 : 3 B 1 : 150 C 3 : 2 D 150 : 1 E 3 : 4
3 $18 is divided in the ratio 2 : 3 . The larger part is:
A $10.80 B $7.20 C $3.60 D $12 E $14.40
4 Calvin spent $3 on his mobile phone for every $4 he spent on music. Calvin spent $420 on
his phone last year. How much did he spend on music for the same year?
A $560 B $315 C $140 D $240 E $525
5 A boat sailed 30 kilometres in 90 minutes. What was the average speed of the boat?
A 15 km/h B 45 km/h C 3 km/h D 20 km/h E 35 km/h
Cambridge Maths NSW
Stage 4 Year 8 Second edition
ISBN 978-1-108-46627-1 © Palmer et al. 2018
Cambridge University Press
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