Here's why:
* Dozen: A dozen is a group of twelve.
* Couple: In this context, "couple" means "two".
Therefore, "a couple dozen" is simply a less formal way of saying "two dozen".
Here's why:
* Dozen: A dozen is a group of twelve.
* Couple: In this context, "couple" means "two".
Therefore, "a couple dozen" is simply a less formal way of saying "two dozen".