Page 118 - MAT KS3 Y8 Cambridge CheckPoint

11.3 Finding percentages

5 In a children’s club there are 23 girls and 14 of them wear glasses.
There are 42 boys and 12 of them wear glasses.
a What percentage of the girls wear glasses?
b What percentage of the boys wear glasses?
c What percentage of all the children wear glasses?

6 The cost of an aeroplane flight increases from $250 to $295.
a What is the increase? b What is the percentage increase?

7 Concert tickets cost $30, $40 or $50.
If you buy a ticket online you pay an extra $3 as a booking fee.
What percentage of each ticket price is the booking fee?

8 This table shows the populations, in millions, of five Country Population (millions)
countries in 1990 and in 2010.
a Calculate the percentage increase in population for 1990 2010
each country over the 20-year period. China 1145 1341
In the same period the world population increased from India 874 1225
5.3 billion to 6.9 billion. Indonesia 184 240
b What was the percentage increase in the world Japan 122 127
population from 1990 to 2010?
c In 2010, what percentage of the world’s population Nigeria 98 158
lived in China? United States 253 310

One billion = 1000 million

9 The table shows the masses of four people who were on Mass in Mass in
a diet from March to July. Person March (kg) July (kg)
a Calculate the percentage change in mass for each person.
A 95.2 88.7
b Who was the most successful dieter? Give a reason
for your answer. B 89.4 79.0
C 84.5 87.3

D 102.5 87.4

10 This table shows a boy’s mass at different ages.
Work out the percentage increase in mass: Age 1 month 1 year 2 years 4 years
a from 1 year to 2 years Mass (kg) 4.5 9.6 12.2 16.3
b from 2 years to 4 years
c from 1 month to 1 year.

116 11 Percentages