A boy of mass 30 kg is sitting at a distance of 2 m from the middle of a see-saw. Where should a boy of mass 40 kg sit so as to balance the see-saw ?

Explanation

To solve the problem of balancing the see-saw with two boys of different masses, we can use the principle of moments. The principle states that for a see-saw to be balanced, the clockwise moments must equal the counterclockwise moments about the pivot point (the center of the see-saw).

### Step-by-Step Solution:

1. **Identify the Masses and Distances**:
- Mass of the first boy (m1) = 30 kg
- Distance of the first boy from the center (d1) = 2 m
- Mass of the second boy (m2) = 40 kg
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