In a conditional probability question, a phrase such as “known to have” limits which outcomes are possible. Use that group’s table total as the denominator, then find the cell where the group meets the requested category for the numerator. Don’t divide by the entire table: the condition has already ruled out outcomes outside the group.
Hints
- Hint 1
A condition is a fact you already know about the selected candy. It narrows the possible picks to one part of the table. Which column total counts only candies that could still be selected?
- Hint 2
The favorable count meets both the known condition and the flavor you want. Find the cell where the kept column crosses that flavor’s row, not the row total. What count is in that cell?
Step-by-step
Restrict to the blue-wrapper column
Step 1Choose the possible group
A condition is something you know about the candy before finding the probability: it has a blue wrapper. So only candies in the blue-wrapper column are possible, and the column total, , is the denominator. The grand total of includes red-wrapped candies, which the condition rules out.
- Step 2
Find the count within that group
The Lemon row crosses the blue-wrapper column at . So candies meet both requirements: blue wrapper and lemon flavor. The lemon row total, , includes red-wrapped candies too.
- Step 3
Calculate the probability
Put the favorable count over the possible count: . The bar means “given that.” Type in Desmos; it shows . Tap the fraction button to see . Keep both counts inside the conditioned group. So the probability that a blue-wrapped candy is lemon is . Choice D.