A manager at a hedge fund company is analyzing three stocks X, Y, and Z with expected returns equal to 0.4, 0.7, and 0.7, respectively. The variance of X, of Y, and of Z is 2. The covariance between X and Y and between Y and Z is 1 and the covariance between X and Z is 0.

1. Find the composition of the minimum variance portfolio.

2. Find another efficient portfolio by setting lambda equals to one and mu equals zero.

3. If the risk-free rate is 0.2, find the tangency portfolio of risky assets.