Respuesta :
Sally's wallet contains the following coins
Quarters = 5
Dimes = 3
Nickels = 8
Pennies = 4
What is the probability that she will choose a dime and then a quarter?
Recall that the probability of an event is given by
[tex]P=\frac{\text{number of favorable outcomes}}{\text{total number of outcomes}}[/tex]The probability that she will choose a dime is given by
[tex]P(dime)=\frac{3}{5+3+8+4}=\frac{3}{20}[/tex]The probability that she will choose a quarter is given by
(note that replacement is allowed so the total number of coins remains the same)
[tex]P(quarter)=\frac{5}{5+3+8+4}=\frac{5}{20}=\frac{1}{4}[/tex]So, the probability that she will choose a dime and then a quarter is
[tex]\begin{gathered} P(dime\: and\: quarter)=P(dime)\times P(quarter) \\ P(dime\: and\: quarter)=\frac{3}{20}\times\frac{1}{4} \\ P(dime\: and\: quarter)=\frac{3}{80} \end{gathered}[/tex]Therefore, the probability that she will choose a dime and then a quarter is 3/80
