I need help with this question, I am a little confused

Question

1. A group of children decide to play a game on a teeter totter that is 3 m in length. One of the children weighing 30 kg, sits on one end of the teeter-totter. The game is to require each of the other children to take turns sitting somewhere along the other end of the teeter-totter to obtain perfect balance. If one of the other children weighs 45 kg, where would that child have to sit on the teeter-totter to obtain perfect balance with the first child? (use the principles of levers)
2. Could any child weighing less than 30 kg obtain perfect balance with the first child? Please explain

Answer 1

Well, you need to know the principle of the level:

(weight)(distance) = (weight)(distance)

Now can you answer?