Just convert everything to decimal form.
So 2 and 3/4 mph = 2.75 mph.
&
9 and 5/8 miles = 9.625 miles.
So, since you want to know how long it would take you to hike 9.625 miles, @ 2.75 mph, you're just going to divide.
9.625 miles / 2.75 mph = 3.5 hours or 3 and 1/2 hours. ( 3 hours, and 30 minutes)