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Home Q & A Board Science-Related Homework Help Mathematics
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Parik Parik
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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.
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#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
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duddyduddy
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9 years ago
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- Master of Science in Biology
- Bachelor of Science

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#3
4 years ago
Thank You for the help!!
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#4
4 years ago
Where is question number 28?
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