Torque on a see-saw type object

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The discussion centers on calculating the supporting force at point Y on a uniform plank XY when the support at point X is moved to point Z, halfway to the plank's center. The correct answer to the problem is 80 N, as derived from the principles of torque and rotational equilibrium. The net torque must remain zero to prevent rotation, leading to the conclusion that the reaction at Z must be twice that of the reaction at Y. The total supporting forces equal 240 N, confirming the calculations.

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Torque on a "see-saw" type object

I had this question on my Physics test last week. I missed it, and it's now time to do test corrections. I have read through the section once again, but I keep on getting the same answer.
torquedrawing.bmp.gif

A uniform plank XY is supported by two equal 120-N forces at X and Y, as shown. the support at X is then moved to Z (half-way to the plank center). The supporting force at Y then becomes:
A. 40
B. 160
C. 60
D. 80
E. 240
I keep getting 60. I know that the net torque must remain 0, so as to keep the object from rotating. That being said, I cannot seem to come up with the correct answer (D).
Here's what my logic was:
If you move the point X, halfway to the center, it will produce 1/2 the amount of torque. So, the force at Y must decrease by 1/2 so as to keep the object in rotational equilibrium.
Please help me cite my error. Thank you in advance
 
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If the force at Z is half the distance (x) that the force at Y is (2x) from the centre,
and the torques must be equal for balance,
then the reaction at Z must be twice that of the reaction at Y.

And, of course, the sum of these two reactions is 240 N.
 

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