Riddle

****UPDATE I fixed the link!

Thanks to Boogster for this one... but I figured it out, so I get to repost it:

This is a real math problem so don’t say that the bus has no legs. If you get the correct answer, that’s the password to the spreadsheet. Put your name in the column with the names (look to the right in the spreadsheet if you open it!), re-save the spreadsheet and then forward it on if you were smart enough to get the right answer.

ARE YOU SMARTER THAN A 5TH GRADER?

There are 7 girls on a bus.
Each girl has 7 backpacks.
In each backpack, there are 7 big cats.
For every big cat there are 7 little cats.

Question: How many legs are there in the bus?

The number of legs is the password to unlock the Excel sheet.
If you open it, add your name, re-save the spreadsheet and send it on to see who else can unlock it.

http://www.yourfilehost.com/media.php?cat=other&file=I__m_Smarter_Than_a_5th_Grader.xls

It's actually just pure math without a trick... which sort of disappointed me a little.