On a fulcrum balance we know that object will be balanced if torque on left side weight is balanced by torque on right side weight
So we know that
(weight of left side) * (distance) = weight of right side) * (distance)
[tex]W_1L_1 = W_2L_2[/tex]
[tex]10 \times 3 = 15 \times r[/tex]
[tex]r = \frac{30}{15}[/tex]
[tex]r = 2 m[/tex]
so the distance of 15 N object must be at 2 m distance from fulcrum
