13. Correct. The answer is false
f(v|2) = (4+v)/22.
Then, the conditional expectation is
E(V|U=2) = ∑v v(4 + v)/22
E(V|U=2)=0(4/22)+1(5/22)+2(6/22)+3(7/22)
E(V|U=2)=19/11.