Question

A bag of dog biscuits contains 7 flavored biscuits. There are 2 cheese biscuits, 3 bacon biscuits, and 2 beef biscuits. Melissa randomly picks one biscuit out of the bag. What is the probability that Melissa picks either a cheese biscuit or a beef biscuit?

Answer 1

SOLUTION

There is a total of 7 biscuits in the bag.

So total outcome = 7

We want to find the probability that Melissa picked either a cheese biscuit or beef biscuit

This becomes the probability of picking cheese biscuit + the probability of picking a beef biscuit

This becomes

$\begin{gathered} \text{probability = }\frac{required\text{ outcome}}{\text{total outcome}} \\ \\ n\text{umber of ch}eese\text{ biscuit = 2} \\ n\text{umber of beef biscuit = 2} \\ \text{Total outcome = 7} \\ \text{Probability = }\frac{2}{7}\text{ + }\frac{2}{7} \\ \\ =\text{ }\frac{2+\text{ 2}}{7} \\ \\ \frac{4}{7} \end{gathered}$

Therefore the required probability is 4/7