How long does a tank of gas last?

So I searched this thread, and did not see this topic. So if it is here I'll apologize in advance.

I bought my son a 2009 RZR 170, it does have the factory big wheel kit. I am wondering what people are getting out of a tank of gas(how long does it run between fill ups). Yes......I know it depends on how, where, and what surface they are ridden.

Just looking for an average time.

Thanks