Friday

August 22, 2014

August 22, 2014

Posted by **Sam** on Monday, October 26, 2009 at 4:40pm.

- math -
**Reiny**, Monday, October 26, 2009 at 4:48pmLet the number of teachers be n

the number of handshakes of n people is

C(n,2)

so C(n,2) = 171

n!/(2!(n-2)!) = 171

n(n-1) = 342

n^2 - n - 342) = 0

(n-19)(n+18) = 0

n = 19 or n= -18, but n > 0

So 19 teachers came

**Related Questions**

7th grade Math - At a faculty costume party, each teacher from transylvania ...

8th grade - At a faculty costume party, each teacher from transylvania Middle ...

Math - Carrie asked 50 randomly selected middle school students at Kind's High ...

math - 5th grade class of 16 students, one-half of the student arrived at school...

algebra - Lincoln High School has 98 teachers. Of the 42 female teachers 8 teach...

Probability - A school has 8 math teachers, 6 English teachers, and 2 geography ...

algebra 2 - Lincoln High School has 98 teachers. Of the 42 female teachers, 8 ...

Math - If the ratio of children to parents is 3 to 2 which of these shows ...

Math - A school has four art teachers, three music teachers, and eight history ...

statistics - What is wrong with the statement: It is believed that the ...