How to formulate mat. investment optimization model (linear programming in lingo)?

Question

Programming

Good afternoon. I need to solve a linear programming problem in the Lingo program. I've never experienced this before, need help. The issue is about investment.
Need to invest 1.5 million or less.
There are 5 possible ways to invest.
1. Invest in shares of company number 1. (reward = 18% risk = 12%)
2. Invest in shares of company number 2. (reward = 16% risk = 8%)
3. Invest in shares of company number 3. (return = 14% risk = 7%)
4. Invest in bonds (reward = 7% risk = 2%)
5. Invest in government bonds (reward = 5% risk = 1%)
There are also some conditions.
It was decided that company number 2. should be invested more than company number 3., but at the same time, company number 2. should be invested less than company number 1.
Investments in bonds should be at least 300 thousand.
Investments in state bonds must be no more than 1 million, but at the same time they must be equal to or greater than the investment in all shares combined.
The total return should be no less than 10%, but at the same time with the condition of the lowest risk.
Does anyone understand this and could show how such a problem is solved?
Thank you!

Answer 1

you build SLAU
you find extrema
xs why LINGO when excel is enough

Answer 2

linprog function in matlab.