As a riddle, the answer is zero legs on the bus since the bus has wheels instead of legs.

But as a maths problem; It's not a tricked question -- just a straightforward maths problem

Confirmed answer is 10990 legs.

§ Let's say the whole situation simply :

- There are 7 girls.

- Each girl has 7 backpack

- Each backpack has 7 big cats

- Each big cat has 7 little small cats.

§ Question: How many legs are there in the bus?

§ Let's focus on each part of the question systematically, write down on a piece of paper if you have to, following my steps of chains.

1. Focus on the first girl first:

A B C D E F G

Girl A has 7 backpacks

2. Now focus on first backpack A1 :

A1 A2 A3 A4 A5 A6 A7

Backpack A1 has 7 big cats

3. Now focus on first big cat :

1 2 3 4 5 6 7

Ø Each big cats have 7 small cats (that's the end of the focus)

Systematically, 7 small cats has 28 legs (7 * 4) combined with the big cat that owns this 7 small cats.

Let's call this the "cat chain", so cat chain 1has 32 legs altogether.

Ø So since there are 7 big cats

7 * 32 = 224 legs

Ø Therefore each backpack has 224 legs

Ø Finally, each girl has 7 * 224 = 1568 legs.

Lastly, since there are 7 girls, A to G, there are 7 * 1568 legs (per girl) = 10976 legs.

Now, since each girl also has 2 legs each;

SO, (7 * 2) + 10976 = 10990 legs altogether

Note: Disregarding bus driver, buses and etc…Only focus on the girl and their backpacks!

There are 7*7 = 49 bags and there are 7 + 7*7 = 56 cats in each bag, meaning there are 56*4 = 224 legs in each bag. So including the 7 children that have 2 legs each, there are 7*2 + 49(224) = 10990 legs in total.

Three

The key to answering this question is knowing what the mathematical term "period" means.

Period: a period is each group of digits separated by commas in a multidigit number.

Example: 30,149,258 is an 8 digit number so each part of the number separated by a comma is 1 period. {30}{149}{258}

I hope this helped.

To cube a number means simply to multiply that number by itself 3 times. To work out 40 cubed you would simply go:

403 = 40 x 40 x 40

40 x 40 = 1,600

1,600 x 40 = 64,000

403=64,000

Therefore, 40 cubed equals 64,000.

The phrase "multiply that number by itself 3 times." can cause confusion.

Sometimes, instead of multiplying it thrice (the number itself) others, due to confusion, just multiply the number by 3... take note it's cube...

What do you get if you multiply 40 by itself once?

Nearly everyone would say 1,600 which is 40².

Multiply that by 40 then seems to mean multiply the answer by 40, giving 64,000 which is then 40 multiplied by itself twice!

Of course some people will say it doesn't matter how many times you multiply 40 by itself you'll always get 1,600.

Just think of 40³ as meaning 3 40s multiplied together and you should avoid any problems.