cook ham 10 to 12 min per lb. and ham is 10 lb. how long do i cook it

Ham is 10 lb. Cooking it for 10-12 minutes per lb. means

For each pound, you cook for between 10 minutes and twelve minutes, then

$${\mathtt{10}}{\mathtt{\,\times\,}}{\mathtt{10}} = {\mathtt{100}}$$  10 pounds for 10 minutes is 100 minutes, or 1hr and 40 minutes.

and

$${\mathtt{10}}{\mathtt{\,\times\,}}{\mathtt{12}} = {\mathtt{120}}$$ 10 pounds for 12 minutes is 120 minutes or 2hr.

 

You cook the ham for between 1hr 40 minutes and 2hr.