Where do i put the numbers on the graph

Witch represents the inverse of the function f(x)=1/4x-12

X^2/100+y^2/25=1 the length of the major axis is: a)5 b)10 c)20

The line plot below represents the number of letters written to overseas pen pals by the students at the waverly middle school. each x represents 10 students. how many students wrote more than 6 and fewer than 20 letters. a.250 b.240 c.230 d.220