Answer:
A i think but i think not also try it
Ed now has $6.09
Firstly
f(x)=3x-2=y then
Interchanging x and y we get
x=3y-2
x+2=3y
y=(x+2)/3
f-1(x)=(x+2)/3
f-1(13)=(13+2)/3
f-1(13)=5