Combinations...1

[mathdad]

Suppose we have a collection of n objects. A combination of these n objects taken r at a time is any selection of r of the objects where order does not matter.

Find the number of combinations of 4 letters w, x, y, z taken three at a time.

Let me see.

{w, x, y}

{w, x, z}

{w, y, z}

{x, y, z}

There are 4 combinations of the letters w, x, y, z.

You say?

 

[Harry_the_cat]

Yes

 

[mathdad]

Yes

Thanks.