For cats :EC72 wrote:The ratio of cats to dogs in a shelter was 7:10 in January. In Febuary, 20 dogs were adopted from the shelter and 32 cats were found by the shelter. The ratio of cats to dogs becomes 22:15 now. Find the number of cats and number of dogs in January.

7u + 32 -> 22p

70u + 320 -> 220p

For dogs :

10u - 20 -> 15p

70u - 140 -> 105p

115p -> 460

1p -> 4

10u - 20 -> 15 x 4 = 60

10u -> 80

1u -> 8

7u -> 56 (cats)

10u -> 80 (dogs)

Ans : 56 cats and 80 dogs.