Knowee
Questions
Features
Study Tools

A man desires to throw a party for some of his friends. In how many ways can he select 7 friends from a group of 14 friends, if the two of his friends(say ’A’ and ’B’) will not attend the party together?

Question

A man desires to throw a party for some of his friends. In how many ways can he select 7 friends from a group of 14 friends, if the two of his friends(say ’A’ and ’B’) will not attend the party together?

🧐 Not the exact question you are looking for?Go ask a question

Solution 1

This problem can be solved using the concept of combinations in mathematics.

Step 1: Calculate the total number of ways to select 7 friends from 14. This can be done using the combination formula C(n, r) = n! / [(n-r)! * r!], where n is the total number of items, r is the number of items to choose, and '!' denotes factorial.

So, C(14, 7) = 14! / [(14-7)! * 7!] = 3432 ways.

Step 2: Calculate the number of ways to select 7 friends when 'A' and 'B' are always together. This means we consider 'A' and 'B' as one unit. So, we now have 13 units (12 remaining friends + 1 unit of 'A' and 'B'). We need to select 6 more units from these 13 units (since 'A' and 'B' are already considered as one unit).

So, C(13, 6) = 13! / [(13-6)! * 6!] = 1716 ways.

Step 3: Subtract the number of ways when 'A' and 'B' are together from the total number of ways to get the number of ways when 'A' and 'B' are not together.

So, the number of ways to select 7 friends such that 'A' and 'B' will not attend the party together = 3432 - 1716 = 1716 ways.

This problem has been solved

Solution 2

This problem can be solved using the concept of combinations in mathematics.

Step 1: Calculate the total number of ways to select 7 friends from 14. This can be done using the combination formula C(n, r) = n! / [(n-r)! * r!], where n is the total number of items, r is the number of items to choose, and "!" denotes factorial. So, C(14, 7) = 3432.

Step 2: Calculate the number of ways to select 7 friends when 'A' and 'B' are always together. This can be done by considering 'A' and 'B' as one unit. So now, we have 13 units (12 remaining friends + 1 unit of 'A' and 'B'). We need to select 6 more units from these 13 units. So, C(13, 6) = 1716.

Step 3: Subtract the number of ways when 'A' and 'B' are together from the total number of ways. So, 3432 - 1716 = 1716.

Therefore, the man can select 7 friends from a group of 14 friends in 1716 ways if 'A' and 'B' will not attend the party together.

This problem has been solved

Solution 3

This problem can be solved using the concept of combinations in mathematics.

Step 1: Calculate the total number of ways to select 7 friends from 14. This is given by the combination formula C(n, r) = n! / [(n-r)!r!], where n is the total number of items, r is the number of items to choose, and '!' denotes factorial. So, C(14, 7) = 3432.

Step 2: Calculate the number of ways to select 7 friends when 'A' and 'B' are always together. This is equivalent to treating 'A' and 'B' as a single entity, so we are effectively choosing 7 items from a group of 13 (12 other friends + 1 entity of 'A' and 'B'). So, C(13, 7) = 1716.

Step 3: Subtract the number of ways when 'A' and 'B' are together from the total number of ways. This gives the number of ways to select 7 friends such that 'A' and 'B' are not together. So, 3432 - 1716 = 1716.

Therefore, the man can select 7 friends from a group of 14 in 1716 ways such that 'A' and 'B' will not attend the party together.

This problem has been solved

Similar Questions

A person has 8 friends. The number of ways in which he may invite one or more of them toa dinner is.(a) 250 (b) 255 (c) 200 (d) none of these

Jimmi and Vishal are planning a dinner party. Vishal has 4 vegetarian friends and 3 non-vegetarian friends, while Jimmi has 3 vegetarian friends and 4 non-vegetarian friends. They decide to invite 4 friends in total and it was decided that both of them will invite two of their friends and also ensure that there are a total of 2 vegetarians and 2 non-vegetarians friends. How many ways can they invite their friends to the dinner party?

After the tryouts for the volleyball team, the coach selects 14 people to join the team. Due to a problem with transportation, only 7 people can travel. In how many ways can the coach pick the people to go?

Select the correct answerIn how many ways can one or more of six friends be invited for a dinner?Options62676393

A lady gives a dinner party for six guests. In how many ways they be selected from among 10 friends

1/3

Upgrade your grade with Knowee

Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.