You are forming an equally weighted portfolio of equities. Many equities have the same beta of 0.84 for factor 1 and the same beta of 1.69 for factor 2. They also have the same expected return of 11 per cent. Assume a two-factor model describes the return on each of these equities.

(a) Write the equation of the returns on your portfolio if you place only five equities in it.

(b) Write the equation of the returns on your portfolio if you place in it a very large number of equities that all have the same expected returns and the same betas.