I don't know if I understand this question that well, but if I am right, the first digit of the question you are asking is 5, and it is in the hundreds place. If this is not what you mean, then can you put more description in this question please?
There are choices when it comes to color (3). Then there is the choice between a boy dog or a girl dog (2). Multiply the number of colors by the number of genders. (6)
When choosing a dog from random, you can either choose:
Brown/M
Brown/F
Black/M
Black/F
Yellow/M
Yellow/F
(This list is called the Sample Space, a list of all possible outcomes)
Because the text says that all types of dogs are found in even numbers, it would not matter if there was 6, 12, 18, ... amount of dogs.
When looking at this sample space, you can see that the chance of choosing a Yellow/F dog, is 1 in 6.
