Answer:43.33 cm mark
Explanation:
Given
mass 1 is located at the 10 cm mark with weight of 15 kg
mass 2 is located at 60 cm mark with weight of 30 kg
string should be attached between them to balance the system
so the distance between the the two masses is 50 cm
For system to be balance torque of both the weight must nullify each other
Let us suppose string is at a distance of x cm from 15 kg mass so 30 kg mass is at a distance of 50-x cm
Balancing torque
[tex]15\times x-30\times (50-x)[/tex]
[tex]x=\frac{100}{3}=33.33[/tex]
so string should be at a mark of 10+33.33=43.33 cm