Grade 12 - More exercises.
Rate, ratio and proportion.
1.
Divide
1.1
R35 in
the proportion 3 : 4.
1.2
45 sweets in
the proportion 2 : 3 : 4
1.3
R34 500 in
the proporion 2 : 8 : 15
2.
Increase
2.1
a length of
21,6 m in the proportion 4 : 7
2.2
a profit of
R3 672 in the proportion 4 : 5
2.3
a mass of
91,7 kg in the proportion 7 : 5
3.
John jogs 5 km
in 25 minutes.
3.1
How long
does he take to jog 2 km?
3.2
How far
can he jog in 65 minutes?
4.
Mary is paid
R30 per hour. She works every day from Monday to Friday, 8 hours per day
4.1
Calculate
her weekly wages.
4.2
How many
hours does she have to work to earn R1 770?
4.3
She worked
for 29 hours. How much will she receive?
5.
A motor car
uses 47,32 litres of petrol to travel 613 km.
5.1
Calculate the
fuel consumption of the car in km/litre and also in litres/100 km.
5.2
How far
can the car travel using 21,4 litres of petrol at the same fuel consumption.
5.3
How many litres
of petrol will the car use to travel 430 km?
6.
A plan is
drawn to a scale of 1 : 50.
6.1
What distance
in real life is represented by a distance of
6.1.1
2 cm on
the plan?
6.1.2
35 mm on
the plan?
6.1.3
0,35 m on
the plan?
6.2
What distance
on the plan is represented by . . . in real life?
6.2.1
35,4 m
6.2.2
0,4 m
6.2.3
1,26 m
mass
7.
The density of
a substance is defined as: density of substance = --------------
volume
7.1
Which
quantity is directly proportional to mass? Explain.
7.2
The mass
of 1 litre of water is 1 kg.
3
Calculate the
density of water in g/cm
3
7.3
The density of
gold is 19,3 g/cm .
3
7.3.1
Calculate the
mass of 6 cm gold.
7.3.2
Calculate the
volume of 413,02 g of gold.
3
7.3.3
It is claimed
that a ring with a mass of 41,2 g and a volume of 2,4 cm is made from pure gold.
Is the claim
correct? Explain your answer.
3
7.4
The mass of
a lead block is 24,97 g and the volume of the block is 2,2 cm .
7.4.1
Calculate
the density of lead.
7.4.2
A second lead
block has a mass of 181,6 gram. Calculate the volume of the block.
7.4.3
A cube is made
of lead. The length of a side is 2 cm. Calculate the mass of the cube.