You have two buckets - one holds exactly 5 gallons and the other 3 gallons. How can you measure 4 gallons of water into the 5 gallon bucket?

(Assume you have an unlimited supply of water and that there are no measurement markings of any kind on the buckets.)

Find the next number in the sequence

1, 2, 6, 21, 88, __?

What has many teeth, but cannot bite?

The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

Solve the rebus riddle in the picture below.

You need to pick one entry from pot A and one from pot B to have a perfect match. Can you do it?

You can see it everyday, But cannot touch it at will. What is it?

I have a head like a cat and feet like a cat, but I am not a cat. What am I?

I am never scared but became petrified and can’t live in a house but would die to make one. What am I?

It's a test that will check your IQ.

Suppose you have one 11 minute hourglass and one 13 minute hourglass.

Can you measure exactly fifteen minutes using them ?