Zach took another long sip of his drink as a way to stall and decide how to answer Jo's question.  He found it was a bit easier to lie to muggles when he actually just told the truth and omitted some strictly wizard things.
"Scotland, actually."  It was a large enough place with some rather remote villages; it was unlikely she'd know of them all.

Except her next answer had him worried and a bit puzzled. A university in Northern Scotland? He didn't know of all the muggle universities, of course, but the ones he did were much more South in Glasgow and Edinburg. He supposed there was one in Aberdeen, but that wasn't quite the North either.

To cover his surprise, Zach took that moment to take another bite of the delightful meat pie. Either he was missing something or Miss Smith was lying about her schooling. Those seemed like the most logical answers since she didn't give any indication she knew of his shop. "I can't say I know of any. Is it a small University?"