SAT TOMORROW NEED HELP!!

[irow247]

Hey this seems really stupid but i have my sat tomorrow and i understand everything on the math section EXCEPT functions. rotten things.

Let the function f(x)=x+1. If 2f(p)=20, what is the value of f(3p)?

J

 

[pka]

If f(x)=x+1 and 2f(p)=20, what is the value of f(3p)?
2f(p)=20 implies f(p)=10.
But f(p)=p+1, so p=9.
f(3p)=f(27)=27+1=28