380 likes | 519 Views
PRACTICE with Permutations and Combinations. Order Order does matters Not matter Don’t Do divide. Divide. Permutations Combinations.
E N D
Order Order does matters Not matterDon’t Do divide. Divide. PermutationsCombinations
1. Find the number of ways that 9 keys can be placed on a key ring. Circular permutation
The formula The numbers The answer 1. Find the number of ways that 9 keys can be placed on a key ring. Circular permutation
The formula n! n The numbers The answer 1. Find the number of ways that 9 keys can be placed on a key ring. Circular permutation
The formula n! n The numbers The answer 1. Find the number of ways that 9 keys can be placed on a key ring. Circular permutation 9! = 9
The formula n! n The numbers The answer 1. Find the number of ways that 9 keys can be placed on a key ring. Circular permutation 9! = 403209
2. In a group of 21 math students, 3 of them will be chosen to go to quiz bowl. In how many ways can the students be chosen for the competition?
2. In a group of 21 math students, 3 of them will be chosen to go to quiz bowl. In how many ways can the students be chosen for the competition? Order Order does matters? Not matter? Don’t Do divide. Divide.
2. In a group of 21 math students, 3 of them will be chosen to go to quiz bowl. In how many ways can the students be chosen for the competition? Order Order does matters? Not matter? Don’t Do divide. Divide.
2. In a group of 21 math students, 3 of them will be chosen to go to quiz bowl. In how many ways can the students be chosen for the competition? The numbers Order Order does matters? Not matter? Don’t Divide.divide. The answer
2. In a group of 21 math students, 3 of them will be chosen to go to quiz bowl. In how many ways can the students be chosen for the competition? The numbers Order Order does matters? Not matter? Don’t Divide.divide. 21x20x19 3! The answer
2. In a group of 21 math students, 3 of them will be chosen to go to quiz bowl. In how many ways can the students be chosen for the competition? The numbers Order Order does matters? Not matter? Don’t Divide.divide. 21x20x19 3! The answer 1330
3. 50 kids enter a contest. In how many ways can they finish in first place and second place?
3. 50 kids enter a contest. In how many ways can they finish in first place and second place? Order Order does matters? Not matter? Don’t Divide.divide.
3. 50 kids enter a contest. In how many ways can they finish in first place and second place? Order Order does matters? Not matter? Don’t Divide.divide.
3. 50 kids enter a contest. In how many ways can they finish in first place and second place? The numbers Order Order does matters? Not matter? Don’t Divide.divide. The answer
3. 50 kids enter a contest. In how many ways can they finish in first place and second place? The numbers Order Order does matters? Not matter? Don’t Divide.divide. 50 x 49 The answer
3. 50 kids enter a contest. In how many ways can they finish in first place and second place? The numbers Order Order does matters? Not matter? Don’t Divide.divide. 50 x 49 The answer 2450
4. The health club gym is open every day. If you are on a certain plan, you can only go 3 days a week. How many 3-day combinations are possible?
4. The health club gym is open every day. If you are on a certain plan, you can only go 3 days a week. How many 3-day combinations are possible? Order Order does matters? Not matter? Don’t Divide.divide.
4. The health club gym is open every day. If you are on a certain plan, you can only go 3 days a week. How many 3-day combinations are possible? Order Order does matters? Not matter? Don’t Divide.divide.
4. The health club gym is open every day. If you are on a certain plan, you can only go 3 days a week. How many 3-day combinations are possible? The numbers Order Order does matters? Not matter? Don’t Divide.divide. The answer
4. The health club gym is open every day. If you are on a certain plan, you can only go 3 days a week. How many 3-day combinations are possible? The numbers Order Order does matters? Not matter? Don’t Divide.divide. 7x6x5 3! The answer
4. The health club gym is open every day. If you are on a certain plan, you can only go 3 days a week. How many 3-day combinations are possible? The numbers Order Order does matters? Not matter? Don’t Divide.divide. 7x6x5 3! The answer 35
5. On Field Day, class groups compete with each other. In the 4th grade class, 30 kids must be paired to run a relay. How many pairings are possible?
5. On Field Day, class groups compete with each other. In the 4th grade class, 30 kids must be paired to run a relay. How many pairings are possible? Order Order does matters? Not matter? Don’t Divide.divide.
5. On Field Day, class groups compete with each other. In the 4th grade class, 30 kids must be paired to run a relay. How many pairings are possible? Order Order does matters? Not matter? Don’t Divide.divide.
5. On Field Day, class groups compete with each other. In the 4th grade class, 30 kids must be paired to run a relay. How many pairings are possible? The numbers Order Order does matters? Not matter? Don’t Divide.divide. The answer
5. On Field Day, class groups compete with each other. In the 4th grade class, 30 kids must be paired to run a relay. How many pairings are possible? The numbers Order Order does matters? Not matter? Don’t Divide.divide. 30 x 29 2! The answer
5. On Field Day, class groups compete with each other. In the 4th grade class, 30 kids must be paired to run a relay. How many pairings are possible? The numbers Order Order does matters? Not matter? Don’t Divide.divide. 30 x 29 2! The answer 435
6. In how many ways can a valedictorian and a salutatorian be chosen from a graduating class of 145 students?
6. In how many ways can a valedictorian and a salutatorian be chosen from a graduating class of 145 students? Order Order does matters? Not matter? Don’t Divide.divide.
6. In how many ways can a valedictorian and a salutatorian be chosen from a graduating class of 145 students? Order Order does matters? Not matter? Don’t Divide.divide.
6. In how many ways can a valedictorian and a salutatorian be chosen from a graduating class of 145 students? The numbers Order Order does matters? Not matter? Don’t Divide.divide. The answer
6. In how many ways can a valedictorian and a salutatorian be chosen from a graduating class of 145 students? The numbers Order Order does matters? Not matter? Don’t Divide.divide. 145 x 144 The answer
6. In how many ways can a valedictorian and a salutatorian be chosen from a graduating class of 145 students? The numbers Order Order does matters? Not matter? Don’t Divide.divide. 145 x 144 The answer 20880