What goes into 27 and 48?

There are 12 boy and13 girls in a class. if the teacher randomly chooses a student’s name out of a hat what is the probability it will be a girl

Gretchen is setting up for a banquet. she has 300 chairs and needs to distribute them evenly among t tables. how many chairs should she put at each table? write your answer as an expression.

What is the range? can’t seem to find it out