How Can I Determine the Weights of Fish A, C, and D in Mobile Equilibrium?

[Isimanica]

Homework Statement

The mobile is in equilibrium. The fish B weighs
27 oz. Determine the weights of fish A, C and D.
(The weights of the crossbars are negligible).

Homework Equations

Moment = Force*Distance

The Attempt at a Solution

My idea here is to use the moments about each point, solve for one variable. Here is what I have com up with so far, am I on the right track?
D(14)=A(4) since their moments at that point are in equilibrium.
B(4)=12(A+D)
C(24)=6(A+B+D)
Am I wrong in setting it up this way?

 

[Borek]

So far so good.

 

[Isimanica]

So then I just say that I set A=D(14)/4
Replace A in equation B(4)=12(D+ (D(14)/4))
Solve for D and then replace D and A values that I get into the equation for
C(24)=6(B+D+A) solve for C and that is it? Please tell me that it wasn't that simple?

 

[Borek]

Please tell me that it wasn't that simple?

As you wish.

It wasn't that simple