Why do this problem:
A
simple problem to get students starting to think about
ratio.
Possible approach :
Ask students to suggest possible combinations and their suggestions
could be written up for everyone in the group to see.
Key questions :

Do all these combinations cost $£5$ per kg? How do
you find out?

Do any of these combinations give identical mixes? How do you
find out?

Are there any relationships between the quantities of the
different ingredients?
Possible extension :
Students can be pressed to explore and articulate more
explicitly the degree of freedom possible within the constraint
that the final mix should cost $£5$ per kg.
Ask students to include a visualisation of why that result
(ratio relationship for Apricots, Nuts & Seeds) might be
expected.
Possible support :
For students who need more support than the text of the
problem.
Ask each student to generate a result price for a ratio mix of
their own choice.
List these mix costs, with the Apricot / Nut / Seed ratio that
produced them as reference for the next task.
Ask students to find ratios of ingredients that will put a
mixture cost per kg in between each value listed.