IF X,Y are independent than Cov(X,Y) $=$ 0 . Here its $\neq$ 0 . So we they are dependent .
E(X+2Y) = E(X) + 2E(Y) = 5 = p
Cov(X,Y) = E(XY) - E(X)E(Y) on solving E(XY) = 3 =q .
Var(X - 2Y + 1) = Var(X) + 4Var(Y) + Var(1) + 2Cov(X,-2Y) + 2Cov(X,1) + 2C(Y,1) [Var[constant]= 0 ]
Cov(X,Y) = 0 if X , Y are independent . So Cov (X,1) = 0 , Cov(Y) =0 .
= Var(X) + 4Var(Y) -4Cov(X,Y) [ Cov(X,-Y) = -Cov(X,Y) ]
On putting the values we get r=5
Therefore pq+r = 20