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# How many different groups of 2 children can ride these toys at one time?

Three children are sharing a bike and a skateboard. How many different groups of 2 children can ride these toys at one time?

### 1 Answer by Expert Tutors

Michael W. | Patient and Passionate Tutor for Math & Test PrepPatient and Passionate Tutor for Math & ...
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Hello NY,

So, this question is asking you for the number of different groups of children who can ride some toys at one time.

- How many total children are there?  Just so we can follow along, let's call that number "N"
- How many children can ride the toys at one time?  That is, how many toys are there?  Let's call that "R"

The question is now, how many different groups of R children can be formed from a total of N children?

Depending on what level of math you're in, those groups of children have a special name.  They're either permutations or combinations.  If those words mean something to you, then the question is:  which one are we talking about here?

If you're not at that level yet, and you have no idea what a combination or a permutation is, then this is a different question.  :)  How about picking names for the N children and seeing how many different ways you can pick R of them?  There aren't too many, so you might be able to count them by hand...

Hope some of this helps,

-- Michael