Final answer:
Percentages represent a portion of a whole and are calculated as a part-to-whole ratio, whether it's brownies eaten from a box, cookies with specific ingredients in relation to allergies, or the probability of selecting a particular flavor or color from an assortment.
Step-by-step explanation:
The student is asking about percentages in the context of portions of items eaten or present in a set. Looking at the given scenarios, we can understand and calculate the respective percentages.
Percentages in Different Scenarios
Jericho's Brownies: If Jericho ate 18 out of 24 brownies, that's 75%. We can calculate this percentage by dividing the number of brownies eaten (18) by the total number (24) and then multiplying by 100.
Assorted Cookies: To calculate the percentage of cookies with certain ingredients, we can use the formula for the probability of an event: P(A) = Number of favorable outcomes / Total number of outcomes. Hence, for chocolate and nuts allergy scenario, P(NEITHER chocolate NOR nuts) = 1 - P(C OR N) = 1 - .40 = .60 or 60%.
For the jar of jelly beans, the probability of selecting a jelly bean of a particular color (for example, blue) can be calculated as P(B) = Number of blue jelly beans / Total number of jelly beans. For blue, 26/150 = approximately 17.33%, which is the probability of picking a blue jelly bean.
Miguel's Cookies: Miguel ate a total of two cookies, and the probabilities for the flavor of the second cookie depend on his first selection. If he picked a chocolate cookie first, the probability of getting another chocolate or butter cookie will change since there is now one less cookie in the box.