some more riddles

[eyTns]

Hello!
I got interested in this topic, so I created some additional examples.
Some may be duplicates. I arranged them in order that seems to work well.
When you test, do not provide the title to LLMs.
I hope you enjoy it.
(I used machine translation to write this issue, but I tested with English version.)

Riddles

lotus flower grows differently

The number of lotus flowers in the pond increases by two every day. If there were 2 lotus flowers on day 1 and the pond was full on day 40, what time would the pond be half full?

Correct Answer: day 20
because it grows linearly

solid bridge

Four people are in front of the bridge. It takes 1 minute for A, 2 minutes for B, 5 minutes for C, and 10 minutes for D to cross the bridge, but you have to move at the slowest pace when several people cross together.
What is the shortest time for four people to cross the bridge?

Correct Answer: 10 minutes
because four people can move together

not from Hanoi

There are 3 sticks. There are 3 disks on the leftmost stick, in order from large to small. What is the minimum number of disk moves to move them to the rightmost stick?

Correct Answer: 3 moves or 1 move
because we can just move

New Year's Special Monty Hall Show

There is a car behind one door and a goat behind the other two. You picked all the doors 1, 2, and 3, and the host opened the door 2 to show that there is a goat. So, would you change your choice?

Correct Answer: No.
because I already picked all three

lonely rabbit

A pair of rabbits give birth to two baby rabbits each year from two years after birth.
If you had one rabbit, how many would it be in 7 years?

Correct Answer: one or maybe zero
because one rabbit cannot produce babies

use scale or should we?

There are 12 coins. One of them is a defective coin that has a different weight from the others. Use the two-arm scale with the least number of times to find out how many coins have a different weight from the others.

Correct Answer: 0 uses of the scale to conclude 1 coin has different weight
because the problem states that

athlete trainee

An athlete and a tortoise compete for a run. The distance is 100 meters, but the athlete starts 100 meters behind the starting point, and the tortoise's speed is twice the athlete's speed. Can athlete catch up with the tortoise?

Correct Answer: No.
because the tortoise is faster

listen to me at least

"It's only wednesday... I wish yesterday was tomorrow... because today would be friday..."
then what day is it today?

Correct Answer: wednesday
because it already said so

say the numbers and end the turn

A and B take turns saying numbers. First player starts with 1 and says some numbers in turn, and the person who says 31 loses. What should A do to start first and win?

Correct Answer: say 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30
because A can.

Thank you.

[cpldcpu]

Thank you, these are very good! Some were quite surprising to me, especially the last one. I modified it a bit:

"A and B take turns naming increasing numbers. Each player can name as many increasing numbers as they want. The first player starts with 1. Then B takes over and so on. The person who says 31 loses. What should A do to start first and win?"

It seems sonnet recognizes this as a variant of the "Nim" game.

It seems the weekday problem and the athlete problem can be solved by 4o and claude.