There are 7 girls on a bus. each girl has 7 backpacks. each backpack has 7 big cats. each big cat has 7 little cats. how many legs are on the bus?

7 girls on a bus, each has two legs. 7 * 2 = 14. 

Each girl has 7 backpacks. So 7 * 7 = 49. 

49 * 7 = 343 cats in total 

343 * 4 = 1,372 cat legs. 

343 * 7 = 2401 small cats 

2401 * 4 = 9,604 cat legs 

14 + 1,372 + 2,401, + 9,604 = 10,990 legs in total

There are seven girls and each girl has seven backpacks so to find the number of backpacks you would multiply 7x7 which equals 49 backpacks on the bus. Each backpack had 7 big cats so to find the number of big cats you would multiply 49x7 which equals 343 big cats. the big cats have 7 little cats so to find the number of little cats you would multiply 343x7 which equals 2401 little cats. Add the number of big cats and little cats. That would be 2744 cats in total. I am going to assume that none of the cats have injuries or deformities so they would all have 4 legs. To find the number of legs in the bus you would multiply the number of cats by 4.