in a certain kindergarten , every child has got either a dog or a cat or both . 18 children have got dogs only and 6 children have got both dogs and cats . if there are 30 children in the kindergarten , how many of them have cats ?
a : only cats b : both cats and dogs c : only dogs as per question , a + b + c = 30 c = 18 b = 6 , so a = 6 . hence , a + b = 12 . answer is b
subtract(30, 18)