Math Quiz: There is a bus with seven (7) girls inside...

This is fun! Let's see if you are a real Math wizard!

Scenario:

There is a bus with 7 girls inside,
Each girl has 7 bags,
Inside each bag, there are 7 Big cats,
Each Big cat has 7 small cats,
All cats have 4 Legs each !

Question: How many Legs are there inside the bus?

I have the excel file that illustrates how the correct answer was arrived. Unfortunately, I cannot upload it here. If you want a copy, leave me a note and an e-mail address or e-mail me privately through the e-mail provided in my profile. I also posted the solution here.