​please help with part C

$200 = R + P + C = \\ \\ R + (3R+4) + C =\\ \\ 4(R+1)+C\\ \\ C = 196-4R$

$E[C] =\\ E[196-4R]=\\ 196-4E[R] = \\ 196-4(2) = 188$

$Var[C] = Var[196-4R] = \\ 4^2 Var[R] = \\ 16Var[R] =\\ 16(1.2) = 19.2$

Thank you!!