Physics help please...theoretical mechanical advantage.?

Question

Ok this may be kinda hard to explain but the question is

What is the theoretical mechanical advantage for each of the three lever systems shown? Since you can't see the pics ill explain wat they look like

Lever 1-a straight bar just sitting there at rest with a triangle underneath it with a box resting on top of it to the far right and then on the far left an arrow pointing down.

Lever 2-Now the triangle is underneath the bar on the far left and the bar is tilted upwards.The box is in the middle and the arrow is on the far left pointing right.

Lever 3-The bar is just sitting again and the triangle is to the far left. the box is on the far right and the arrow is pointing up in the middle.

OK i understand that that probably made ZERO sense but maybe if you are a physics expert you can make some sense of it. Or atleast someone can explain to me how you figure out theoretical mechanical advantage just by looking at picture!! THANKS SOOO MUCH!!!

the question doesn't give any measurments

Answer 1

This is about torque and leverage.

sum the torques about the tip of the triangle.

Lets's say the bar is 2 m long and the box weighs 10 kg

if the triangle is in the middle, the force necessary to raise the box is equal to 10*g

If the triangle is moved closer to the box, say .5 m away, now compute the torques:

10*g*.5=F*1.5

see how the Force gets multiplied by a bigger number?
This is mechanical advantage, or leverage.

j

Answer 2

the answer is 1, 2, 0.5

Answer 3

right answer aaaaaay