Which is not a combination?
A. choosing 3 toppings for you pizza
B. lining 3 students up in a row
C. choosing 2 desserts from a tray of 10
D. choosing 5 students to represent a class of 30
I think its D. Am I right? Thanks.
Sorry I meant B.
Ye, you're right.
okay thanks!
To determine which option is not a combination, we need to understand what a combination is. In combinatorial mathematics, a combination is a way of selecting items from a larger set where the order of the selection does not matter.
Let's analyze each option to see if it fits the definition:
A. Choosing 3 toppings for your pizza: This is a combination since the order in which you choose the toppings does not matter. If you choose pepperoni, mushrooms, and olives, or olives, mushrooms, and pepperoni, it is still the same combination.
B. Lining 3 students up in a row: This is a permutation, not a combination. Permutations take order into account. If the order of the students matters, then this option is not a combination.
C. Choosing 2 desserts from a tray of 10: This is a combination because the order in which you choose the desserts does not matter. If you choose a slice of cake and a cookie, or a cookie and a slice of cake, it is still the same combination.
D. Choosing 5 students to represent a class of 30: This is also a combination since the order in which the students are chosen does not matter.
Based on this analysis, it is clear that option D (choosing 5 students to represent a class of 30) is also a combination, and it is not the correct answer. Therefore, your initial guess that the answer is D is incorrect.
The correct answer is B. Lining 3 students up in a row, which is a permutation.