# Discrete math

posted by .

There are eighteen guard posts. How many ways can 25 not indistinguishable (That is, they are distinguishable.)guards be distributed to the guard posts, so that no post is empty?

Try - (25 choose 18) ??

• Discrete math -

Think of it this way:

Every time all the 18 posts are filled, there will be a set of 7 guards left out.
So the question becomes, how many set of 7 from 25 can we find, which is
C(25,7) or C(25,8) , both yield the same answer.

BTW, your clarification in brackets is a contradiction
you probably meant to say
((That is, they are NOT distinguishable.)

## Similar Questions

1. ### Economics/Marginal Analysis

21st Century Electronics has discovered a theft problem at its warehouse and has decided to hire security guards. The firm wants to hire the optimal number of guards. The follwoign table shows how the number of security guards affects …
2. ### Economics

21st Century Electronics has discovered a theft problem at its warehouse and has decided to hire security guards. The firm wants to hire the optimal number of guards. The follwoign table shows how the number of security guards affects …
3. ### criminal justice

hi, I just need some ideas in how to make a SOP Standard operating procedure for guard behavior in a correctional. I think I will be including things like guard fraternization with prisoners, treatment of prisoners of the opposite …
4. ### economics marginal cost analysis

Vaska Electronics has discovered a theft problem at its warehouse and has decided to hire some security guards. The following table shows the number of security guards and the amount of theft per week: (#of security guards)(#of stolen …
5. ### TSU

Twenty-first century electronics has discovered a theft problem at its warehouse and has decided to hire security guards. The firm wants to hire the optimal number of security guards. The following table shows how the number of security …
6. ### Math-6-grade (Anonymous)

Sorry Anonymous that I deleted your post by mistake, but here's the answer to the question: "there are four posts on each side of a square fenced-in are. How many posts are there in all?
7. ### criminal justice

After some recent incidents involving guard mistreatment of prisoners at your local correctional institution, you have been tasked to draft a sample standard operating procedure (SOP) for guard behavior. Create an SOP that addresses …
8. ### managerial economics

Twenty first century electronics has discovered a theft problem at its warehouse and decided to hire security guards. The firm wants to hire the optimal number of security guards. The following table shows how the number of security …
9. ### Math

Thomas puts fence posts from one end of a field to the other, equal distance apart. There are 287 posts. Width of each post is 10 cm. Distance between two posts is 30 meters. Find Length of fence.
10. ### Math help

How many squares in this figure? (1 point) 4.) 15 5** 20 10** Crystal wants to put a fence around her vegetable garden.Her garden is 5 ft wide and 4 ft long.She plans to put a post at each corner and at every foot.How many fence posts

More Similar Questions