Like in situation with High Sierra You have only one easy way to make Mac OS X 10.10.5 Yosemite Install USB.

We’ll use Terminal.

I sold macbook pro os x yosemite to my friend, and this post for him.

This video shows how to make Mac OS X 10.10.5 Yosemite Install USB in Terminal.

You CAN {Download}

Install MacOS Yosemite.dmg