Can you explain the question below step by step how to solve this and point you used to graph this question, I am confused to how to graph this? 1. An investor has $50,000 to invest in a CD and a...

Can you explain the question below  step by step how to solve this and  point you used to graph this question, I am confused to how to graph this?

1.
An investor has $50,000 to invest in a CD and a mutual fund. The CD yields 4​% and the mutual fund yields 7​%. The mutual fund requires a minimum investment of $12,000​, and the investor requires that at least twice as much should be invested in CDs as in the mutual fund. How much should be invested in CDs and how much in the mutual fund to maximize the​ return? What is the maximum​ return?