**Answer:**

There are 4 questions to answer here and the answers are given below:

1. COMBINATION

2. SET 2

3. {S2, S3, S4, S5}

4. { } OR ∅

**Step-by-step explanation:**

The key topics here are PERMUTATION & COMBINATION and SETS & VENN DIAGRAMS.

The assignment has 5 questions in all. The options for each question are listed below and separated by commas:

1. True, False

2. True, False

3. A, B, C, D

4. A, B, C, D

5. A, B, C, D

Mr. Montes derives his answers from a **random answer generator**; same way Amisha generated her answers by **random selection**.

<u>QUESTION 1</u>

If you want to find the odds that Amisha got at least 3/5 of the answers correctly, would you use a permutation or a combination?

<u>ANSWER TO QUESTION 1</u>

You would use a **combination.** Note that as much as 'permutation' is distinctly defined from 'combination', in many complex cases both are used to derive the solution. In this case though, a combination is used. For each of the 5 questions, there are a number of possible answers. Questions 1 and 2 have only <em>two possible answers</em> (also known as **options**) while questions 3, 4 and 5 have <em>four possible answers</em>/<em>options</em> to choose from. Amisha can only have one set of five answers; each to each question. So this is a combination! If you want to find the odds that Amisha got at least 3 of her 5 answers correct, you would use a combination of the various possible answers to check.

<u>QUESTION 2</u>

Find "Set 1 ∩ Set 2" and explain the notation in the sentence.

<u>ANSWER TO QUESTION 2</u>

First list out relevant information:

- The correct answers to questions 3, 4 and 5 are respectively **C, B, A**

- The universal set consists of five students: S1, S2, S3, S4, S5 hence

Ц = {S1, S2, S3, S4, S5}

Next, enlist the elements of each defined set

Set 1: {S1, S2, S3, S4, S5} Set 2: {S2, S3, S4} Set 3: {S4, S5}

**Note: **Set 1 is equal to the universal set.

Now this notation "∩" means "intersect". It requires an action - checking out which elements in one set also appear in a second set and then bringing those elements to form a new set.

In the case of this question, we're to find **Set 1 intersect Set 2**. The elements present in Set 1 and also present in Set 2 are {S2, S3, S4}.

If you look closely, you'll observe that these are the same elements in Set 2! This brings to remembrance, one of the laws of sets:

**The intersect of any subset and the universal set (recall that Set 1 happens to be equal to or have the same elements as the universal set) is equal to that subset.**

So the answer to question 2 is

Set 1 ∩ Set 2 = Set 2

<u>QUESTION 3</u>

Find "Set 2 ∪ Set 3" and explain the notation in the sentence.

<u>ANSWER TO QUESTION 3</u>

The notation ∪ represents "union". This is the act of putting together the elements in two sets, to form a new set. In this activity, if an element appears in both sets, it is only written **once **in the new set, not twice.

So, Set 2 union Set 3 = {S2, S3, S4, S5}

As earlier stated, **Student 4 **isn't appearing twice in the new set.

<u>QUESTION 4</u>

Find the ' of Set 1 and explain the notation in this sentence.

<u>ANSWER TO QUESTION 4</u>

The symbol ' means "complement of a set". Finding the complement of a set is like subtracting the elements of that set from the universal set.

Since Set 1 contains the same elements as the universal set, subtracting Set 1 from the universal set will give you nothing. In this case, **the complement of Set 1 is a null set!**

Set 1 ' Ц = { } or ∅

where the empty bracket symbol and the slashed zero symbol represent null set.

Kudos!