A large beaker of water is placed on a scale, and the scale reads 40 N. A block of wood with a weight of 10 N is then placed in the beaker. It floats with exactly half of its volume submerged. Assuming that none of the water spilled out of the beaker when the block was added, what does the scale read now?

1. 40 N
2. 45 N
3. 50 N
4. None of the above.

The scale, which is at the bottom of the pile, has to support the entire weight of everything on top of it. The scale reads 50 N.