Escaping the Tower

A Queen is captured in the top room of a very high tower, along with her son and daughter. Outside their window, there is a pulley with a rope around it, and two identical baskets fastened at the ends of the rope. The queens weigh 195lbs, the daughter weighs 105lbs, and the son weighs 90lbs. If any of them gets in a basket and weighs 15lbs more than the contents in the other basket, he/she will fall too fast and will die upon impact with the ground. How can the three escape the tower, using the two baskets and one 75lbs stone they have in their room?

1. The stone is sent down in a basket.
2. The son goes down, the stone goes up.
3. The daughter goes down, the son goes up.
4. The stone is thrown back down.
5. The queen goes down, the daughter and the stone go up.
6. The stone goes down.
7. The son goes down, the stone goes up.
8. The daughter goes down, the son goes up.
9. The stone is thrown back down.
10. The son goes down, the stone goes up.

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