What numbers should go on the bottom line?
3 6 9 15
8 2 10 12
11 8 19 27
19 10 29 39
? ? ? ?

There's one "sport" in which neither the spectators nor the participants know the score or the leader until the contest ends.

What is it?

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

You need to move three matchsticks to form three squares. Can you do it?

What Does this text mean:

important=important

This is a famous paradox which has caused a great deal of argument and disbelief from many who cannot accept the correct answer. Four balls are placed in a hat. One is white, one is blue and the other two are red. The bag is shaken and someone draws two balls from the hat. He looks at the two balls and announces that at least one of them is red. What are the chances that the other ball he has drawn out is also red?

What is the last thing you take off before bed?

Which letter of the alphabet has the most water?

In a jungle where there are no street lights or any other artificial source of lights, I notice a black snake crossing the road.
How did I get sight of the snake?

Andrew’s doctor gives him three pills and tells him to take one every half hour. How much time will have passed by the time Andrew’s taken all three pills?