Free body diagram of man in a box

[1/2"]

Homework Statement

A 60 kg man stands in a 30 kg box on a light weighing machine.
If the box is kept at rest due to force applied by the man by the rope , what is the weight shown by the weighing machine?

Homework Equations

The Attempt at a Solution

.answer given in book is 15 kg.
But if the net force man i think will his weight-weight of the box=300N
I don't think i am proceeding correctly.
I just need a hint for the free body diagram.
Thanks in advance

 

[tiny-tim]

hi 1/2"!

as often in these problems, you need two free body diagrams …

in this case, one for the man (on his own), and one for the man-and-box …

how many external forces forces are there in each case? ​