How Do I Include Tension in a Free Body Diagram?

[okgo]

Homework Statement

Homework Equations

I already got the right answer in the book. The only issue I have is drawing the free body diagram which it doesn't show. I'm not sure how to include the tension of the bottom-most string into the first diagram.

The Attempt at a Solution

Its meant to say 72 N for the first diagram

 

[Dr.D]

There are two downward forces on the upper block. One is the gravity force, its own weight, and the other is the tension in the sring due to the weight of the lower block. Thus your FBD for the upper block needs two down arrows.