year 8 maths

5B
Simplifying ratios
283
Example 4b
Example 5
8 Simplify the following ratios. Use a calculator to check your answers.
a 1 1 2 : 3
b 2 1 4
5 : 3
5
c 3 1 3 : 1 2 5
d 4 1 3 : 3 3 4
9 First change the quantities to the same unit, and then express each pair of quantities as a ratio in
simplest form.
a 12 mm to 3 cm b 7 cm to 5 mm
c 120 m to 1 km d 60 mm to 2.1 m
e 3 kg to 450 g f 200 g to 2.5 kg
g 2 tonnes to 440 kg
h 1.25 L to 250 mL
i 400 mL to 1 L j 20 minutes to 2 hours
k 3 hours to 15 minutes l 3 days to 8 hours
m 180 minutes to 2 days
n 8 months to 3 years
o 4 days to 4 weeks p 8 weeks to 12 days
q 50 cents to $4 r $7.50 to 25 cents
PROBLEM-SOLVING AND REASONING
10, 11, 14 11, 12, 14, 15
11–13, 15–17
10 Which of these ratios is the simplest form of the ratio 1 2 : 2 ?
1
1
A 2 :
B 1 : 4
C
2
4 :1 D 1 : 1
11 Kwok was absent from school on eight days in Term 1 . There were 44 school days in Term 1 .
Write the following ratios in simplest form.
a ratio of days absent to total days
b ratio of days present to total days
c ratio of days absent to days present
12 Over the past four weeks, the Paske family has eaten takeaway food for dinner on eight occasions.
They had hamburgers twice, fish and chips three times, and pizza three times. Every other night
they had home-cooked dinners. Write the following ratios in simplest form.
a ratio of hamburgers to fish and chips to pizza
b ratio of fish and chips to pizza
c ratio of takeaway dinners to home-cooked dinners
d ratio of home-cooked dinners to total dinners
13 When Lisa makes fruit salad for her family, she uses 5 bananas, 5 apples, 2 passionfruit, 4 oranges,
3 pears, 1 lemon (for juice) and 20 strawberries.
a Write the ratio of the fruits in Lisa’s fruit salad.
b Lisa wishes to make four times the amount of fruit salad to take to a party. Write an equivalent
ratio that shows how many of each fruit Lisa would need.
c Write these ratios in simplest form:
i bananas to strawberries ii strawberries to other fruits
14 Feng incorrectly simplified 12 cm to 3 mm as a ratio of 4 : 1 . What was Feng’s mistake and what is
the correct simplified ratio?
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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