Quantitative Analysis;Question is in description

Question

There are 14 people who work in an office. If each person sends each other person at the office one e-mail on a particular day and there is only one e-mail between every possible pair, how many e-mails will be sent that day?

answer?

Answer 1

N, #people    E, # emails
—————      -----------
2                       1
3                       2
4                       6
5                     10

The pattern is E = (N*(N-1))/2 (this can be proven, but I'll leave that as an exercise)

Plugging in N=14 and you will find E=91

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NOTE that I assumed "If each person sends each other person at the office one e-mail on a particular day, unless they've already received an email from that person" based on "… there is only one e-mail between every possible pair."

 

 

 

 

N, #people          E, # emails

—————           -----------

     2                       1

     3                       2

     4                       6

     5                      10

 

The pattern is  E = (N*(N-1))/2      (this can be proven, but I'll leave that as an exercise)

 

Just plug in N=14 and you will find E=91

 

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NOTE that I assumed  "If each person sends each other person at the office one e-mail on a particular day, unless they've already received an email from that person"  based on  "… there is only one e-mail  between every possible pair."