5) - Let the following information be about 4 different portfolios: E(RA) = 3% y JA = 10%, E(RB) = 5% y og = 10%, E(RC) = 5% y oc = 15%, E(Rp) = 7% y op = 20%. Determine which portfolios are NOT efficient and why ... * Note: detail the procedure (by hand), both for the formulas and for the resolution