
For each subset it can either contain or not contain an element. For each element, there are 2 possibilities. Multiplying these together we get 27 or 128 subsets. For generalisation the total number of subsets of a set containing n elements is 2 to the power n.
A biased example: Asking students who are in line to buy lunch
An unbiased example: Asking students who are leaving/going to lunch(<em>NOT buying </em><em>lunch</em><em />).
But in this case, the answer choices can be... confusing.
Don't panic! You're given numbers and, of course, your use of logic.
Answer choice A: 100 students grades 6-8
Answer choice B: 20-30 students any <em>one</em> grade<em></em><em>
</em>Answer choice C: 5 students
<em></em>Answer choice D: 50 students grade 8
An unbiased example would be to choose students from <em>any grade.</em> So we can eliminate choices B and D.
Now, the question wants to <em>estimate how many people at your middle school buy lunch.</em> This includes the whole entire school, and if you are going to be asking people, you aren't just going to assume that if 5 people out of 5 people you asked bought lunch, the whole school buys lunch.
So, to eliminate all bias and/or error by prediction, answer choice A, the most number of students, is your answer.
Answer:
What is the difference between entering a formula and entering data ??
Answer:
8 
Step-by-step explanation:
Find the LCD of the two fractions, which is six
3
= 3 
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5
+ 3
= 8
The next step is to reduce:
8
= 8
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Have a great summer :)