Question 1194088
<br>
P(at least one cat) = 1-P(no cats) = 1-P(4 dogs)<br>
The probability of selecting 4 dogs and 0 cats is<br>
{{{(C(7,4)*C(6,0))/C(13,4) = 35/715 = 7/143}}}<br>
Another way to calculate the probability of choosing 4 dogs is to look at the probabilities that choosing the animals one at a time produces the desired outcome.<br>
P(dog on first selection) = 7/13
P(dog on second selection) = 6/12
P(dog on third selection) = 5/11
P(dog on fourth selection) = 4/10<br>
P(all dogs) = (7/13)(6/12)(5/11)(4/10) = 7/143<br>
So the probability of choosing at least 1 cat is<br>
ANSWER: 1 - 7/143 = 136/143<br>