Here we use the following notation:

• REO — real estate objects.

     General properties of the task:

• mode of investment — to buy alien real estate;
• payback factor — absent;
• the need for statistical modeling — not is.

     Given:

• number of investment options, for each of them are given:
  • investment amount, which consists of two parts:
    • investor's own funds;
    • credit funds, involved by him;
• interest rate on the loan;
• 3 restrictions for the choice of REO;
• a set of REO available for purchase, for each of them are given:
  • possible sign of selecting the REO before applying restrictions;
  • REO sample description;
  • its cost;
  • number of REO upgrade options, for each of them are given:
    • description of this option;
    • REO upgrade cost;
    • duration of its upgrade;
    • expected proceeds from subsequent sale of the REO.

     Maximized quality criterion: absolute income from the sale of purchased REO after their possible upgrade.