10,990 legs.
Each backpack contains 7 big cats plus 7 kittens for each big cat. That is a total of 56 felines per backpack.
Each girl is holding 7 backpacks containing a total of 392 felines.
There are 7 girls, so collectively they are carrying 2,744 felines with 4 legs each, which makes a total number of 10,976 legs.
Add to this the 14 legs of the 7 girls. There is a total of 10,990 legs in the bus.

Back

-----------------------------------------------------------------------------------------------------------------------------------------------------