Whenever we have "AND" in a probability question, it means "x" [multiplication].
When we have "OR" in a probability question, it means "+" [addition].
Here, we want Probability of Quarter [P(q)] OR Probability of Dime [P(d)].
So, we will add the individual probabilities.
Now,
Total Coins = 7 + 11 + 8 + 15 = 41
Number of Quarters = 7
Number of Dimes = 11
So, we find individual probabilities:
P(q) = 7/41
and
P(d) = 11/41
Now, we add them up:
[tex]\begin{gathered} P(q)+P(d)=\frac{7}{41}+\frac{11}{41} \\ =\frac{18}{41} \end{gathered}[/tex]
To get percentage, we do the division and multiply by 100.
18 divided by 41 = 0.4390
Multiply by 100:
0.4390 * 100 = 43.90%
