A, B,C, D and E please

Arbor Systems and Gencore stocks both have a volatility of 50%. Compute the volatility of a portfolio with 50% invested in each stock if the correlation between the stocks is (a)1.00, (b) 0.50, (c) 0.00, (d) - 0.50, and (e) - 1.00. In which of the cases is the volatility lower than that of the original stocks