Relations - GRE Subject Test: Math

Card 0 of 20

Question

What is the value of ?

Answer

When you see a letter with the prime symbol, that means complement. Complement tells you to take whatever is NOT in that set and what is in the universal set. You could also say you are eliminating the numbers in the universal set that are in the set you are complementing.

The universal set is

Set

Taking the numbers 7, 8, 9, and 10 out of the universal set you get the answer

Compare your answer with the correct one above

Question

Evaluate

Answer

The prime symbol means to take the complement of set D. To find a complement, you want to only include the numbers in the universal set that do not appear in the set being complemented.

If set

and the universal set is

The numbers you want to include are everything in the universal set except 4, 9, 10, 11, and 12

This leaves the numbers

Compare your answer with the correct one above

Question

Evaluate

Answer

A complement symbol means you want to only include the numbers in the universal set that do not appear in the set being complemented.

However, all the numbers in the universal set appear in itself. This means the complement of ANY universal set is the empty set.

Compare your answer with the correct one above

Question

Evaluate

Answer

Always work in parentheses first. First, you need to solve the union of sets A and B. Union means to include everything in both sets without repeating any duplicates.

Now take the complement of this by including the numbers in the universal set that do not appear in A union B. This leaves

Compare your answer with the correct one above

Question

If angle , find angle if angles and are complementary.

Answer

Step 1: Recall the definition of Complementary angles.

Two angles are complementary if the sum of the two angles is ALWAYS .

Step 2: If the sum of the angles is , then we can subtract the other one to find the missing angle...

So,

Compare your answer with the correct one above

Question

Use DeMorgan's law to write a statement that is equivalent to the following statement

Answer

The easiest way to remember DeMorgan's law is that you flip the symbol upside down (which changes union to intersection and vice versa), complement both sets (remembering that the complement of a complement is just that set), and either remove parentheses or add parentheses and place the complement symbol outside of it.

Flip the symbol from an intersection to a union, complement both sets, and remove the parentheses.

is equivalent to the original statement

Compare your answer with the correct one above

Question

Using DeMorgan's law, which of the following is equivalent to the statement

Answer

The easiest way to remember DeMorgan's law is that you flip the symbol upside down (which changes union to intersection and vice versa), complement both sets (remembering that the complement of a complement is just that set), and either remove parentheses or add parentheses and place the complement symbol outside of it

Flip the intersection symbol to a union, complement both sets, and add parentheses with the complement symbol outside of it.

Compare your answer with the correct one above

Question

Using DeMorgan's law, is the statement equivalent to ? If not, choose the correct statement that is equivalent.

Answer

The easiest way to remember DeMorgan's law is that you flip the symbol upside down (which changes union to intersection and vice versa), complement both sets (remembering that the complement of a complement is just that set), and either remove parentheses or add parentheses and place the complement symbol outside of it.

Flip the union symbol to an intersection, complement both sets, add parentheses and a complement symbol outside the parentheses.

Compare your answer with the correct one above

Question

Using DeMorgan's law, is the statement equivalent to ? If not, choose the correct statement that is equivalent.

Answer

The easiest way to remember DeMorgan's law is that you flip the symbol upside down (which changes union to intersection and vice versa), complement both sets (remembering that the complement of a complement is just that set), and either remove parentheses or add parentheses and place the complement symbol outside of it.

Flip the union symbol to an intersection symbol, complement both sets, and remove the parentheses

Compare your answer with the correct one above

Question

Using DeMorgan's law, which of the following is equivalent to the statement

Answer

The first step is to realize that the C and intersection symbol in the original question are distractions and have nothing to do with applying DeMorgan's Law.

In the parentheses, flip the symbol from an intersection to a union and complement both sets.

Normally, with only two sets, you should eliminate the parentheses that was there to show that the complement symbol applied to the entire parentheses. However, with three sets you still need to know the order in which to work out the problem so you should keep the parentheses around B and A.

Compare your answer with the correct one above

Question

Using DeMorgan's law, is the statement equivalent to ? If not, choose the correct statement that is equivalent.

Answer

The easiest way to remember DeMorgan's law is that you flip the symbol upside down (which changes union to intersection and vice versa), complement both sets (remembering that the complement of a complement is just that set), and either remove parentheses or add parentheses and place the complement symbol outside of it.

Flip the union symbol to an intersection symbol, complement both sets, and remove the parentheses.

Compare your answer with the correct one above

Question

Let be the universal set of all people. Let be the set of all people who like Band A. Let be the set of all people who like Band B. Let be the set of all people who like Band C. Let stand for Julianna.

Let . Which of the following could be true?

Answer

, which is the intersection of and . It follows that and .

, so it follows that Julianna likes Band A. The three choices that state that she does not can be eliminated.

. This is the union of , the complement of - that is, the set of people not in - and . It follows that either Julianna does not like Band B, does like Band C, or both. Therefore, it is not true that she likes Band B and does not like Band C. This can be eliminated.

The only possible choice is that Julianna likes Band A and Band C, but not Band B.

Compare your answer with the correct one above

Question

Let be the universal set of all people. Let be the set of all people who are dancers and be the set of all people that are singers.

Let represent Jeremy. Which of these statements states the opposite of "Jeremy is not a dancer, but he is a singer" in set notation?

Answer

In set notation, "Jeremy is not a dancer, but he is a singer" can be stated as

That is, Jeremy falls in the intersection of the complement of the set of dancers and the set of singers .

The opposite of this is that is in the complement of this set:

By DeMorgan's law, this is equivalent to saying

, or

.

Compare your answer with the correct one above

Question

Let universal set be the set of all people. Let represent Brittany.

Let be the set of people who like James Blunt, , the set of people who like John Legend, and , the set of people who like Pharrell Williams.

True or false: Brittany likes James Blunt, John Legend, and Pharrell Williams.

Statement 1:

Statement 2:

Answer

Assume Statement 1 alone. is the intersection of the sets , , and . Since Brittany falls in this intersection, she falls in all three sets, and it follows that she likes all three of James Blunt, John Legend, and Pharrell Williams.

Assume Statement 2 alone. is the union of the three sets. Since Brittany falls in this union, she falls in one, two, or all three sets, which means that she likes at least one of James Blunt, John Legend, and Pharrell Williams. However, more information is needed before it can be established whether or not she likes all three.

Compare your answer with the correct one above

Question

What is ?

Answer

means the intersection of set A and set C. Intersection means that you want to choose only the numbers that are in BOTH set A and set C. The only numbers that are in common to those two sets are 3 and 9.

Compare your answer with the correct one above

Question

What is ?

Answer

means the union of set B and set C. Union means to include all the numbers that are in either set B or set C (without listing duplicates twice). The numbers 1, 3, 5, 8, 9, and 11 appear in B and the numbers 2, 3, 5, 6, 9, 12 appear in C. Including all of those numbers in the set symbol gives the correct answer.

Compare your answer with the correct one above

Question

What is the intersection of :

Set A={}
Set B={}

Answer

Step 1: Recall the definition for intersection of two sets: The intersection of two sets is a subset that has numbers that is shared between two sets, A and B.

Step 2: Find the shared elements between both sets

Set A and Set B both share 4,11, and 14.

The intersection of both sets is {}

Compare your answer with the correct one above

Question

What is the union of the following sets:

Set A={}
Set B={}

Answer

Step 1: Define the union of two sets. The union of two sets is all elements that are in two sets, as well as the elements that are shared.

Step 2: Find the union of the sets:

Set A has elements:
Set B has elements:

Union of Set A and B () is {}

Compare your answer with the correct one above

Question

What is the intersection of Set A: and Set B:

Answer

Step 1: Define what the intersection of two sets means.. The intersection of two sets is defined as a set that has elements that are shared between both original sets..

Step 2: Find any shared elements..

If we look, Set A and Set B do not share any elements..

Therefore, there is no intersection of the two sets.

Compare your answer with the correct one above

Question

Evaluate

Answer

This question asks you to find the intersection of the sets B and D. Include only the numbers that both sets have in common with one another. The only common number with both sets is 4.

Compare your answer with the correct one above

Tap the card to reveal the answer