Question

17) List the ways five dogs a Beagle, a Collie, a Greyhound, a Poodle and a

Answer 1

Answer:

• 10 pairs

• It is a combination

Explanation:

This is a combination because the order does not matter: the Beagle - Collie couple is the same as the Collie - Beagle couple, so it is only counted once.

The formula for combinations is:

           $C(m,n)=\dfrac{m!}{n!\cdot (m-n)!}$

For five diffferent dogs to be put in pairs, the number of different pairs is:

         $C(5,2)=\dfrac{5!}{2!\cdot (5-2)!}=\dfrac{5\times 4}{2}=10$