First find the total number of animals Martha's cat catches: 3 rats + 7 birds = <<3+7=10>>10 animals
Then multiply that number by 5: 10 animals * 5 = <<10*5=50>>50 animals
Then subtract 3 to find the total number of animals Cara's cat catches: 50 animals - 3 animals = <<50-3=47>>47 animals
#### 47