nnn this is the reason I'm majoring in biology
Based off my limited high school physics skils:
It says you already have torque and the paperback's lever arm, so using the formula they gave you at the top substitue to find the force. Then use the formula F=mxg, substitue the force for F and gravitaiton constant for g and you should get mass?
Edit: Mass and weight are not the same thing dddd
but I'm pretty sure using the torque you found and the lever arm in the formula they gave (torque = force x lever arm) to find force is a step in the right direction.
any takers?