Math Brain Teaser

A friend sent an email to me that had the following riddle enclosed:

For those of you who excel at logic questions…….. Can you figure this one out? The answer will be in numbers, not spelled out.

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?

My answer: Why are there so many cats stuffed into backpacks and why isn’t PETA assaulting this bus to free these poor cats?

I guess I’m not “logical.”