How to calculate these values in biomechanics?

[Tsunnnami]

Homework Statement

So there is given that the muscles of the neck support the head and thus exert an M force. The head is 3kg = 30N.

Homework Equations

We got to calculate the M and F forces.

The M force has to be 25 and F 45 . I know this because we got the answers.

The Attempt at a Solution

No idea how those values were calculated, please help

https://ibb.co/hip9BH

 

[Voq]

Photo is bad quality so i don't see details very well. But what i see is that you have certain distance between this forces as well..

 

[Voq]

Also this solutions are not correct for this poor example. You would get G=20N if M=25N and F=45N. On picture is says G=30N.
First of all i think F should be 30N according to nature of problem and the question would be to find forces M and G on muscles if distance between is x,y.