Look at this sequence from top to bottom. What is the next number in the sequence?
1
11
21
1211
111221
312211

Can you quickly find which two matchstick figures are identical?

You have two strings whose only known property is that when you light one end of either string it takes exactly one hour to burn. The rate at which the strings will burn is completely random and each string is different. How do you measure 45 minutes?

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

Find the hidden tiger in the given optical illusion ?

John speaks the truth only once a day in a week. Below are a few hints for you:

First: Days are Sunday, Monday and so on.
Second: One day he says, "I lie on Monday and Tuesday".
Third: On the next day, he says, "Today is either Thursday, Saturday or Sunday".
Fourth: On the next day, he says, "I lie on Wednesday and Friday".

Can you identify the day on which he speaks the truth?

Can you replace the question mark with the correct letter?

6 + 6 + 6 = N
7 + 7 + 7 = E
8 + 8 + 8 = R
0 + 0 + 0 = ?

Can you name three consecutive days without using the words Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, or Sunday?

Can you name some countries which do not have the alphabet 'A' in them?

You have a three-gallon and a five-gallon measuring device. You wish to measure out four gallons.