Why is the Hole below a Lock?

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 name any English verb that becomes its past tense by simply rearranging the alphabets ?

A certain street contains 100 buildings. They are numbered from 1 to 100. How many 9's are used in these numbers?

Every words stands for unique digit that makes the arithmetic equation true

SEVEN + SEVEN + SIX = TWENTY.

What are the digits ?

What is the next number in the series?

15 29 56 108 208 ?

There are three light switches outside a room. One of the switches is connected to a light bulb inside the room.
Each of the three switches can be either 'ON' or 'OFF'.

You are allowed to set each switch the way you want it and then enter the room(note: you can enter the room only once)

Your task is to then determine which switch controls the bulb?

In case you were starting to feel confident, this one was meant for third graders in Vietnam. The answer is 66, but we don't blame you for scratching your head about how they got there.

What is more useful when it is broken?

What breaks yet never falls, and what falls yet never breaks?