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Desired outcome counting with letters

Teaching Transcript

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How many different ways can we draw 2 vowels from this set of tiles?

The important thing to note is that only the vowels matter, we have 3 of them, and we are looking to pick 2 of the 3 in any order.

So that's 3 choose 2. We can write it in either notation, in the first, its the 3 first and the 2 second to mean 3 choose 2. In the bracketed, or binomial notation, it's the 3 on top.

The factorial equation for 3 choose 2 is 3 factorial, divided by, 2 factorial times 3 - 2 factorial.

If we calculate that out, that's 3 ways to pick 2 vowels.

This math skill teaches how to calculate the number of ways to choose a subset of vowels from a set of vowels, using combinations. It emphasizes understanding and applying the formula for combinations, represented as "n choose k", and calculating it using factorials.

Skill Practice

Counting ways to pick N vowels from M vowels in a set of tiles

Test your understanding of desired outcome counting with letters by practicing it! Work through the below exercises to use it in practice.