An investor considers putting $100,000 in two stocks: stock A and stock B today. Stock A offers an Expected Return of 0.0035 and a risk of 0.003, while stock B offers an Expected Return of 0.0018 and a risk of 0.001. As you can see, Stock A offers higher reward but also higher risk than Stock B.

1. Find the optimal combination of how much to invest in each stock to get the maximum profit, and the amount of that profit, considering that you can only accept a risk (Standard Deviation) of 140 (30p)

2. As the investor increases the maximum acceptable level of risk (to 160, 200, 230) what happens with the amount invested in each stock? (10p)

3. As the investor increases the maximum acceptable level of risk (to 160, 200, 230) what happens with the expected total profit? Does it change? In what sense? Why?