All SAT Math Resources
Example Questions
Example Question #5 : Permutation / Combination
At a deli you can choose from either Italian bread, whole wheat bread, or sourdough bread. You can choose turkey or roast beef as your meat and provolone or mozzarella as your cheese. If you have to choose a bread, a meat, and a cheese, how many possible sandwich combinations can you have?
10
8
7
12
14
12
You have 3 possible types of bread, 2 possible types of meat, and 2 possible types of cheese. Multiplying them out you get 3*2*2, giving you 12 possible combinations.
Example Question #1892 : Psat Mathematics
Shannon decided to go to nearby café for lunch. She can have a sandwich made on either wheat or white bread. The café offers cheddar, Swiss, and American for cheese choices. For meat, Shannon can choose ham, turkey, bologna, roast beef, or salami. How many cheese and meat sandwich options does Shannon have to choose from?
10
20
30
35
25
30
2 bread choices * 3 cheese choices * 5 meat choices = 30 sandwich choices
Example Question #1 : Permutation / Combination
An ice cream parlor serves 36 ice cream flavors. You can order any flavor in a small, medium or large and can choose between a waffle cone and a cup. How many possible combinations could you possibly order?
108
144
216
172
72
216
36 possible flavors * 3 possible sizes * 2 possible cones = 216 possible combinations.
Example Question #841 : Arithmetic
Example Question #1721 : Sat Mathematics
A group of friends decide to go out to the movies. Fred and Tom are bringing dates, while their 2 friends are going alone. When the friends arrive at the movie theater, they find a row of six seats so they can all sit together.
If Fred and Tom must sit next to their dates, how many different ways can the group sit down?
Think of the seats as an arrangement of people in a line. Fred and Tom must sit next to their dates, so you can treat the pair as a single object. The only difference is that we must then multiply by 2, since we can switch the order in which they sit down at will (either Fred or his date can sit on the left).
So instead of dealing with 6 objects, we now simply work with 4. An arrangement of 4 objects, can be made in different ways. You can choose any of 4 objects to be in the first spot. Once that spot is taken, you move onto the next of four spots. You place any of the remaining three there, giving you 3 more choices (or multiplying by 3). You do the same thing 2 more times to end up with 24 possibilities.
Finally, you have to take into account switching the positions of Fred/Tom and their respective dates. Since there are two pairs, you multiply by 2 twice. This gives you
different arrangements.
Example Question #1722 : Sat Mathematics
For a certain lunch special, customers must order a salad, an entree, and a dessert. If there are three different salads, four different entrees, and two different desserts available, then how many different lunch specials are possible?
9
72
18
24
12
24
Customers must choose a salad, an entree, and a dessert. There are three different salads, four entrees, and two desserts.
The simplest way of determining the number of combinations is by multiplying the number of options for each part of the meal. In other words, we can find the product of 3, 4, and 2, which would give us 24.
Sometimes, if you can't think of a way to mathetimatically determine all of the different combinations of something, it helps to write out as many as you can. Let's write out all of the possible cominbations just to verify that there are 24. Let's call the different salads S1, S2, and S3. We will call the four entrees E1, E2, E3, and E4, and we will call the desserts D1 and D2.
Here are the possible lunch special combinations:
S1, E1, D1
S1, E1, D2
S1, E2, D1
S1, E2, D2
S1, E3, D1
S1, E3, D2
S1, E4, D1
S1, E4, D2
S2, E1, D1
S2, E1, D2
S2, E2, D1
S2, E2, D2
S2, E3, D1
S2, E3, D2
S2, E4, D1
S2, E4, D2
S3, E1, D1
S3, E1, D2
S3, E2, D1
S3, E2, D2
S3, E3, D1
S3, E3, D2
S3, E4, D1
S3, E4, D2
The answer is 24.
Example Question #1723 : Sat Mathematics
There are five pictures but only four display cases. The display cases are unique. How many different arrangements of pictures in display cases can be created?
120
5
24
50
240
120
There are five possible choices for the first space. For the second there are four possible, three for the third, and two for the fourth. 5 * 4 * 3 * 2 = 120 possible arrangements.
Example Question #11 : Permutation / Combination
Ernie has 4 shirts, 7 ties, and 3 pants. How many different possible outfits can Ernie make?
The purpose of this question is to understand how to calculate a number of combinations. All different combinations of clothing articles are equally possible. Since all combinations are possible, the numbers of articles of clothing are all multiplied together, , yielding 84 different possible outfits.
Example Question #1724 : Sat Mathematics
Gihani has six clean shirt and four pairs of pants to choose from. How many possible combinations of outfits can she make with these items?
If she has six shirts and four pairs of pants, then the total number of options she has can be found by multiplication.
To double check, you can create a tree diagram, listing the possible combinations.
Example Question #16 : Permutation / Combination
Refer to the above diagram.
How many ways can a route be drawn that goes from Point A, to Point B, to Point C, then point A again, in that order?
The multiplication principle can be applied here. There are 5 ways to get directly from Point A to Point B, 3 ways to get directly from Point B to Point C, and 2 ways to get directly from Point C to Point A. Multiply:
possible routes.