I have no doors but I have keys, I have no rooms but I have space, you can enter but you can’t leave! What am I?

Jim and Sarah are in a long-distance relationship. Jim buys an engagement ring for Sarah and wants to mail it to her. Unfortunately, the only way to ensure the ring will be received is to place a lock on the package. Jim has locks and Sarah has locks, but neither has keys for each other’s locks. How can they make sure the ring isn’t stolen?

When my father was 31 I was 8. Now he is twice as old as me. How old am I?

What is the largest number you can write with just 3 digits?

It has a long neck, A name of a bird, Feeds on cargo of ships, It's not alive,

What is it?

What four weights can be used to balance from 1 to 30 pounds?

You’re out on the water and see a boat filled with people. You look away for a second and look back again, but this time you don’t see a single person on the boat. Why? Hint: The boat did not sink.

Can you find out which number multiplied by itself will give the output as 12345678987654321?

I inserted a coin in a bottle and closed its mouth with the help of a cork. Now, I was able to take the coin out from the bottle without taking out the cork or breaking the bottle. Can you tell me how I did it?

What is the four-digit number in which the first digit is one-third the second, the third is the sum of the first two, and the last is three times the second?