A centimetre ruler is put on a picture of a cat. The scale of the picture to the real cat is $1:2$1:2.

What is the height of the real cat, from its ears to its toes?

This horse is next to a centimetre ruler. The scale of the picture to a real horse is $1:20$1:20.

This kangaroo is next to a centimetre ruler. The scale of the picture to a real kangaroo is $1:10$1:10.

This elephant is next to a centimetre ruler. The scale of the picture to a real elephant is $1:100$1:100.