Question

Leslie is a biologist. She is going to randomly select one animal from her lab to study. There are 5 salamanders, 3 crayfish, and 12 minnows in her lab. What is \text{P(salamander}

Answer 1

Since there are a total of 20 animals (5+3+12) and there are 5 salamanders, the probability she chooses a salamander is 5/20 -> 1/4, 25%, or .25

Answer 2

The sample space contains three types of animals; 5 salamanders, 3 crayfish, and 12 minnows.

So population of sample space would be, n(S) = Salamanders + Crayfish + Minnows.

n(S) = 5 + 3 + 12 = 20.

She wants to randomly select an animal and check if it is Salamander or not.

population of favourable outcomes would be, n(salamander) = 5.

Now the probability for selecting a salamander would be :-

`P(salamander) = (n(salamander))/(n(S)) \\\\ P(salamander) = (5)/(20) \\\\ P(salamander) = (1)/(4) \;or\; 0.25 \;or\; 25\%`