PROBLEM 6. Consider three securities A, B and C with expected returns of 10%, 15% and 12%, respec- tively, and standard deviations 8%, 18% and 20%. The correlation coefficients are 0.7 between A and B, 0.1 between A and C. and 0.4 between B and C. What is the portfolio on the efficient frontier that corresponds to an expected return of 12%