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Understanding

O There are 6 sparrows and 9 woodpeckers on a tree.
a) What is the ratio of the number of woodpeckers to the number of sparrows?
b) Express the number of sparrows as a fraction of the number of woodpeckers.
© The number of blue beads in a bag is | of beads in the bag.
total
the
number
of
a) What is the ratio of the number of blue beads to the number of beads that are not blue in the bag?
b) What is the ratio of the number of beads that are not blue to the total number of beads in the bag?
the
number
of
of
© The number of girls at a concert is | children at the concert.
a) What is the ratio of the number of girls to the number of boys at the concert?
b) What is the ratio of the number of boys to the total number of children at the concert?
O Yan has 9 hairbands, May has 6 hairbands and Fiona has 6 hairbands.
a) What is the ratio of the number of hairbands May has to the number of hairbands
Yan has to the number of hairbands Fiona has?
b) Express the number of hairbands Yan has as a fraction of the total number of hairbands that
the girls have.
© There are 40 girls, 32 boys and 16 adults at a party.
a) What is the ratio of the number of girls to the number of boys to the number of adults in the simplest form?
b) Express the number of adults as a fraction of the total number of people at the party.
o I of the children in a class are boys.
8
a) What fraction of the class are girls?
b) What is the ratio of the number of boys to girls?
o I of the hibiscus plants in a garden are red. The rest are yellow.

What is the ratio of the number of red hibiscus plants to the number of yellow hibiscus plants?
o I of the audience in a cinema are women.

What is the ratio of the number of men to the number of women in the cinema?

13.1.1 Equivalent ratios and simplifying

ratios

You learnt about equivalent fractions and expressing fractions in the simplest form.
Similarly, we can simplify ratios or find equivalent ratios of any given ratio.

Finding equivalent ratios

Example 1

Molly used the information in the table below to prepare some lemonade.

Number of glasses of blended lemon 1 2
Number of glasses of water
3 6
Blended lemon : Water (simplest form) 1 :3 1 :3

UNIT 13 I Ratio, Rate and Proportion