Latest riddles

If answer A would be correct, then answer B ("Answer A or B") would also be correct. If answer B would be correct, then answer C ("Answer B or C") would also be correct. This leads to the conclusion that if either answer A or answer B would be the correct answer, there are at least two correct answers. This contradicts with the statement "there is only one correct answer to this question". If answer C would be correct, then there are no contradictions.

Therefore, the solution is answer C.

In your bedroom, you have a drawer with 2 red, 4 yellow, 6 purple, 8 brown, 10 white, 12 green, 14 black, 16 blue, 18 grey, and 20 orange socks. It is dark in your bedroom, so you cannot distinguish between the colors of the socks.
How many socks do you need to take out of the drawer to be sure that you have at least three pairs of socks of the same color?

Answer

In the worst case in which you did not take three pairs of socks of the same color, you took 2 red socks, 4 yellow socks, and 5 of each of the other colors. That gives a total of 46 socks. Then if you take one more sock, you are sure to have 6 socks of at least one color. Therefore, you have to take 47 socks from the drawer to be sure that you have at least three pairs of socks of the same color.

A man has a wolf, a goat, and a cabbage. He must cross a river with the two animals and the cabbage. There is a small rowing boat, in which he can take only one thing with him at a time. If, however, the wolf and the goat are left alone, the wolf will eat the goat. If the goat and the cabbage are left alone, the goat will eat the cabbage.
How can the man get across the river with the two animals and the cabbage?

Answer

1. First, the man takes the goat across, leaving the wolf with the cabbage. Then he goes back. Next, he takes the wolf across. Then the man goes back, taking the goat with him. After this, he takes the cabbage across. Then he goes back again, leaving the wolf with the cabbage. Finally, he takes the goat across.
2. First, the man takes the goat across, leaving the wolf with the cabbage. Then he goes back. Next, he takes the cabbage across. Then the man goes back, taking the goat with him. After this, he takes the wolf across. Then he goes back again, leaving the wolf with the cabbage. Finally, he takes the goat across.