Extending Mixing Colours

1
Extending Mixing Colours
I am learning to solve difficult ratio problems.
Do not start this lesson unless you have an
excellent understanding of Mixing colours.
2
The tables below show different mixtures for
making green paint. green is made from mixing
blue and yellow. The greater the proportion of
blue, the darker the green.
Mixture A Mixture A Mixture B Mixture B Mixture C Mixture C
Blue Yellow Blue Yellow Blue Yellow
2 3 3 6 10 15
23 23 36 36 1015 1015
To work out which mixture is lightest we can
convert the ratios into percentages.
In Mixture A 2 parts are blue out of the 5
parts (2 3 5)
We know from earlier lessons that is the same
as or 40.
As a fraction that is
2 5 0.4
40
We can also work out the percentage by
3
Now lets work out the percentage for Mixture B.
Mixture A Mixture A Mixture B Mixture B Mixture C Mixture C
Blue Yellow Blue Yellow Blue Yellow
2 3 3 6 10 15
23 23 36 36 1015 1015
40 40
In Mixture B 3 parts are blue out of the 9
parts (3 6 9)
This is the same as or 33.3.
As a fraction that is
3 9 0.333
33.3
We can also work out the percentage by
4
Now lets work out the percentage for Mixture C.
Mixture A Mixture A Mixture B Mixture B Mixture C Mixture C
Blue Yellow Blue Yellow Blue Yellow
2 3 3 6 10 25
23 23 36 36 1015 1015
40 40 33.3 33.3
In Mixture C 10 parts are blue out of the 25
parts (10 15 25)
This is the same as or 40.
As a fraction that is
10 25 0.4
40
We can also work out the percentage by
5
Its easy to see now that Mixture B would make
the lightest green as it has the smallest
percentage of blue.
Mixture A Mixture A Mixture B Mixture B Mixture C Mixture C
Blue Yellow Blue Yellow Blue Yellow
2 3 3 6 10 25
23 23 36 36 1015 1015
40 40 33.3 33.3 40 40
6
Now lets complete the percentages row for the
table below. Again, we want to find out which mix
will make the lightest green.
Mixture A Mixture A Mixture B Mixture B Mixture C Mixture C
Blue Yellow Blue Yellow Blue Yellow
7 13 4 6 8 17
713 713 46 46 817 817

35
40
32
7 13 20
4 6 10
8 17 25
8 25 0.32
4 10 0.4
7 20 0.35
2) Express the amount of blue as a fraction.
1) Find the total number of parts.
3) Convert this fraction to a decimal and then a
percentage.
7
Now try these questions on your own.
Complete the percentages row of the table below
so that you can find the mix that will make the
darkest green. You may use a calculator to help
you with the division.
Click again when you have worked out all the
percentages.
Mixture A Mixture A Mixture B Mixture B Mixture C Mixture C
Blue Yellow Blue Yellow Blue Yellow
4 16 6 9 8 17
416 416 69 69 515 515

20
40
25
Which mixture will make the darkest green?
Mixture B
Need some more practise? Try Teacher Tools
Fractions, Decimals and Percentages Book Numeracy
resources