2
Mark makes a model of the Burj Khalifa tower
10
Exam-style question
using a ratio of 1 : 2400.
A school organises a baking competition.
The height of his model is 345 mm.
Four classes take part. Each student can
What is the height of the Burj Khalifa tower
only enter one item in the competition.
in metres?
One class enters cakes and loaves of bread
in the ratio 3 : 1.
Q2 hint
1 : 2400 means that 1 mm in the
model represents 2400 mm in real life.
There are 6 loaves of bread entered in the
competition.
3
Write each ratio as a whole
Example
All the entries from the other classes
number ratio in its simplest
are cakes.
form.
The same number of students take part from
a
0.3 : 6
each class.
b
3.2 : 4.8
How many students take part in the
c
36 : 1.5
competition altogether?
(4 marks)
d
14.4 : 25.6
4
Write each ratio as a whole number ratio in
11.3
Ratios and measures
its simplest form.
a
0.3 : 1.25
b
37.8 : 6.3
1
Write these ratios in their simplest form.
c
12.5 : 13.75
a
1 hour : 20 minutes
d
28.8 : 61.2
b
750 ml : 1 litre
5
P
Windows are made in standard ratios.
c
8 mm : 2 m
Type A are made in the width : height ratio of
Q1 hint
Both parts of the ratio need to be in
5 : 6, and Type B are made in the ratio 5 : 8.
the same units before you simplify.
Is each of these windows Type A or Type B?
a
b
2
A can contains 250 ml of cola and a bottle
3156 mm
contains 2 litres of cola.
4224 mm
Write down the ratio of the amount of cola in
2630 mm
the can to the amount of cola in the bottle.
2640 mm
Give your answer in its simplest form.
3
6
Complete these conversions.
Brass screws are made from copper and zinc
Example
in the ratio 84.5 : 45.5.
a
64 000 g =
kg
Write this ratio in its simplest form.
b
4.7 litres =
ml
c
135 mm =
cm
7
The ratio of fat : flour in a recipe is 3 : 8.
d
3.6 km =
m
Aziz uses 75 g of fat.
How many grams of flour should he use?
4
1 mile ≈ 1.6 km. Convert
a
8 km to miles
8
R
The ratio of potato : cauliflower in a potato
b
62 miles to km.
and cauliflower curry recipe is 9 : 15.
c
The distance from Paris to Brussels by car
Sanjay uses 420 g of cauliflower.
is 305 km. How far is this in miles?
He has 300 g of potato.
Will he use all of the potato?
1
5
A recipe needs 1
pints of milk.
2
9
a
1 pint = 20 fl. oz (fluid ounces).
Huw splits his weekly pocket money into
1
spending money and money saved to buy a
Convert 1
pints to fluid ounces.
2
laptop in the ratio 17 : 13.
b
1 fl. oz ≈ 28 ml. Convert your answer to part
He gets £15 each week.
a into millilitres.
How much money does he save each week?
86
11.2 Using ratios 1
R = Reasoning P = Problem-solving