Question

There are four mammals (one dog and three cats) and three reptiles (one snake and two turtles) on sale at a drastic discount at the local pet store. what is the probability that the first two animals sold are both cats?

Answer 1

Total animals = 4 + 3 = 7
Number of cats = 3
P (cat + cat) = 3/7 * 2/6 = 1/7

Answer 2

Probability of an event = Number of favorable outcomes/ total outcomes

Here there are 4 mammals of which 1 is a dog and three are cats

Also there are three reptiles of which one is a snake and two are turtles.

So in all there are 7 animals.

Of all these 7 , 3 are cats

So the probability to chose the first animal as cat is 3/7

Now there are 2 cats left and 6 animals are left

The probability for the second to be cat is 2/6 = 1/3

The probability of choosing both cats

`=((3)/(7))((1)/(3) )`

`=(1)/(7)`

The probability of choosing both cats is 1/7