You would like to invest up to $1, 000. You can invest your money in stocks and loans. Each dollar invested in stocks yields 10 cent profit, and each dollar invested in a loan yields 5 cent profit. At least 30% of all money invested must be in stocks, and at least $400 must be in loans.

Formulate an LP that can be used to maximize total profit earned from your investment (You need to clearly define decision variables, generate the objective function and constraints).