If eleven plus two equals one, what does nine plus five equal?

John was running from 40 thieves. John has got 3 gold boxes which weigh as 4kg, 2kg, and 1kg respectively. A witty man asked John to stay with him for seven days in exchange for 1kg gold per day. John needs to stay there for seven days and also do not want to give the witty man any advance. How can John pay for his seven days stay?

Using four sevens (7) and a one (1) create the number 100. Except for the five numerals, you can use the usual mathematical operations (+, -, x, :), root and brackets ()

How is a fly different from a mosquito?

How many times in a given day, minutes and hour clock comes in a straight line ?

You want to boil a two-minute egg. If you only have a three-minute timer (hourglass), a four-minute timer and a five-minute timer, how can you boil the egg for only two minutes?

Name a key which is hardest to turn.

Can you make four (4) nines (9) equal 100?

Which three-digit number, made of consecutive digits, like 567, is 2 less than a cube and 2 more than a square?

This puzzle is for Harry Potter fans. Do you know why Tom Riddle is called Lord Voldemort?