Top Posters
Since Sunday
w
3
w
3
e
3
3
r
3
2
b
2
M
2
V
2
f
2
c
2
c
2
Home Q & A Board Science-Related Homework Help Mathematics
New Topic  
Parik Parik
wrote...
Go to Answer
Posts: 22
Rep: 1 0
9 years ago
Any help is greatly appreciated! Also is anyone else taking classes through ILC right now?

26.   Use the quadratic formula to solve for n in: C(n,2) = 45. Show your calculations.

27.   Prove that C(50,3) + C(50,4) = C(51,4)

28.   From a group of six women and five men, determine how many ways a committee of four people can be selected with
a)   Two women and two men.
b)   Three women and one man.
Show your calculations.
Read 584 times
4 Replies
Replies
wrote...
#1
Staff Member
9 years ago
Quote from: Parik (9 years ago)
26.   Use the quadratic formula to solve for n in: C(n,2) = 45. Show your calculations.

c (n,2) = n!/2!(n-2)!

= n (n-1) / 2

so

n (n-1) /2 = 45

n^2 - n = 90

n^2 - n - 90 = 0

(n+9) (n-10) = 0

so that

n = -9 or n = 10

since negative value can be discarded,

so,

n = 10
- Master of Science in Biology
- Bachelor of Science
Answer accepted by topic starter
duddyduddy
wrote...
#2
Staff Member
Top Poster
Posts: 7813
Rep: 1650 16
9 years ago
Sign in or Sign up in seconds to unlock everything for free
1
- Master of Science in Biology
- Bachelor of Science

Related Topics

wrote...
#3
4 years ago
Thank You for the help!!
wrote...
#4
4 years ago
Where is question number 28?
New Topic      
Quick Reply
Explore
Post your homework questions and get free online help from our incredible volunteers
  1280 People Browsing
Start New Topic Take the Tour CoursesNew Study Tools Topics Trending Browse by Textbook
Live Chat
Related Images
  
 96
  
 385
  
 334
Your Opinion
Who will win the 2024 president election?
Votes: 119
Closes: November 4
Previous poll results: Which of the following is the best resource to supplement your studies: