The image presents three math problems related to combinatorics. Problem 1: Two distinct dice are thrown. Find the number of possible outcomes where the sum of the numbers on the dice is either 5 or 6. Problem 2: There are 3 types of taxis available to travel to/from a village and a nearby town. When going to the town, a person can take any of the taxis or walk. However, on the way back, they decide to take a taxi. How many ways are there for them to travel to and from? Problem 3: There are 6 men and 5 women. They need to form mixed-gender pairs to play badminton. How many ways can these pairs be formed?
2025/5/21
1. Problem Description
The image presents three math problems related to combinatorics.
Problem 1: Two distinct dice are thrown. Find the number of possible outcomes where the sum of the numbers on the dice is either 5 or
6.
Problem 2: There are 3 types of taxis available to travel to/from a village and a nearby town. When going to the town, a person can take any of the taxis or walk. However, on the way back, they decide to take a taxi. How many ways are there for them to travel to and from?
Problem 3: There are 6 men and 5 women. They need to form mixed-gender pairs to play badminton. How many ways can these pairs be formed?
2. Solution Steps
Problem 1:
Let's list the possibilities for each sum:
For a sum of 5: (1,4), (4,1), (2,3), (3,2). There are 4 possibilities.
For a sum of 6: (1,5), (5,1), (2,4), (4,2), (3,3). There are 5 possibilities.
Since the sum can be 5 or 6, we add the number of possibilities: 4 + 5 =
9.
Problem 2:
On the way to the town, the person can choose one of the 3 taxis or walk. So there are 3 + 1 = 4 options.
On the way back, the person can only choose a taxi. So there are 3 options.
The total number of ways is the product of the number of options for each trip: 4 * 3 =
1
2.
Problem 3:
We need to choose one man and one woman to form a pair.
There are 6 choices for the man.
There are 5 choices for the woman.
The total number of possible pairs is the product of these choices: 6 * 5 =
3
0.
3. Final Answer
Problem 1: 9
Problem 2: 12
Problem 3: 30