We want to investigate what different types of relationships occur in the situations given below. Each situation will relate to a set of things such as:
All cars in the UK.
and a question asked such as:
What colour is the car?
For each situation we want to consider the following questions:
Is there always an answer?
Could there be multiple answers for each person/place/number?
Could different people/places/numbers have the same answer as each other?
Is there always an answer?
Yes, every car is coloured in some way (even if it is multi-coloured).
Could there be multiple answers for each person/place/number?
This depends on what we think about cars that have more than one colour. We could say, no there is only one answer for each car, by including a ‘multi-coloured’ category. Or we could say, yes some cars are more than one colour.
Could different people/places/numbers have the same answer as each other?
Yes, for example lots of cars are red.
A map of the Himalayas.
A place is at height \(\quantity{x}{m}\) above sea level. Where is it on the map?
People who were eligible to vote in the last General Election.
Who did you vote for?
People who voted in the last General Election.
Who did you vote for?
You and your friends
Who do you and your friends follow on Twitter?
All real numbers
A number is rounded to the nearest whole number. What is it?
People
What does your right thumb print look like?
In this instance, we are not counting ‘no-one’ or ‘there isn’t one’ as answers.