**12. Incorrect. The answer is false, not true:**

(a) Using the results of Problems 6 and 7 we have

f(v|u) = f(u,v)/f_{1}(u)

f(v|u) = [(2u+v)/42]/f_{1}(u),

so that with u=2

f(v|2) = [(4v)/42]/(11/21)

f(v|2) = (4+v)/22

(b) P(V=1|U=2)= f(1|2)

P(V=1|U=2)= 5/22.