If you need to cook a turkey at 350 for 1 hour and a ham at 325 for 1hour and 15 minutes and need both of them done at the same time how long should you cook them in the same oven at what temperature?

I wouldn't recommend cooking both at the same time. I would cook your ham first, and then your turkey.

That being said it can also depend on how big your oven is. If you have a commerical size oven then go ahead. The thing is that you need to make sure that both your turkey and ham reach a internal temperature over 180 degrees. This will ensure that all the bacteria is cooked out. I would cook at 375 if I had a big enough and spacious oven to do so.