Q: Hi. I bought ipad from second hand and i want to ask how to delete i cloud without password?  Last owner didnt delete it.

You can't.  You'll need the password to remove the icloud account.

You'll need to contact the previous owner and have them remove it.

Have them follow this support document:

What to do before selling or giving away your iPhone, iPad, or iPod touch - Apple Support

Then there is nothing you can do. Return the iPad to where you bought it and demand a refund.