Solving these riddles in the best way I can:
- A man is replacing a wheel on his car, when he accidentally drops the four nuts used to hold the wheel on the car. They fall into a deep drain, irretrievably lost. A passing girl offers him a solution that enables him to drive home. What is it?
I guess that would be to lend him her car, or to give him spare nuts.
- Two Russians walk down a street in Moscow. One Russian is the father of the other Russian’s son. How are they related?
They are both the parents of the child, man and woman.
- What occurs once in June, once in July and twice in August?
The letter U
- Six drinking glasses stand in a row, with the first three full of water and the next three empty. By handling and moving only one glass at a time, how can you arrange the six glasses so that no full glass stands next to another full glass, and no empty glass stands next to another empty glass? What is the minimum number of moves to solve this puzzle?
Pore the second full glass into the second empty glass and put it back in its position. Lifting, poring, and putting back gives to or three moves, depending on how you count the action. If you switch places between the second full and the second empty, you need three steps: moving the second full glass out of the way, replacing it with the second empty. Then placing the full one in its place.