Here's a
that was sent to me by my nephew.
Give it a try and see if YOU can solve it.
(Don't forget to time yourself.)

Look at the following series of 5 (five) numbers and calculate what the 6th (sixth) number will be. When you think you have the correct answer, click on MY SOLUTION. then enter your answer as your password. If you are correct, the Excel file will open and you can add your name and information, THEN you can send this website address to your friends and see it THEY can solve it.

It's said that engineers take 2 minutes to resolve this, architects 3 hours and doctors 6 hours, Supervisors/Managers 10 hours. Nurses never do...

1, 2, 6, 42, 1806, ???????