Question

Bob needs $.50 to ride the bus. He has 3 quarters, 5 dimes, and 2 nickels. What is the probability he will pull two quarters in a row from his pocket without replacement? Show work.

Answer 1

Step 1:

Probability formula

$\text{Probability of any event = }\frac{n\text{umber of required outcomes}}{n\text{umber of possible outcomes}}$

Step 2:

Number of possible outcomes

Quarters = 3

Dimes = 5

Nickels = 2

Total possible outcomes = 10

Step 3:

$\begin{gathered} \text{Probability of picking two quarters one after the other without} \\ \text{replacement = }\frac{3}{10}\times\frac{2}{9}=\frac{1}{15}\text{ } \end{gathered}$

Final answer

The probability he will pull two quarters in a row from his pocket without replacement = 1/15