SOLUTION: A club can elect a member as president and another member as treasurer in 506 different ways. How many members does the club have?

Algebra.Com
Question 896212: A club can elect a member as president and another member as treasurer in 506 different ways. How many members does the club have?
Answer by jim_thompson5910(35256)   (Show Source): You can put this solution on YOUR website!
Let's say we had x members total

That means we have x choices for president (assuming they are all candidates).

That leaves us with x-1 choices for treasurer. We cannot pick the same person to run both positions.

-------------------------------------------------------

So we have x*(x-1) ways to pick 2 people (from a pool of x people)

We know that there are 506 ways to do this, so x*(x-1) = 506

-------------------------------------------------------

Solve for x

x*(x-1) = 506

x^2-x = 506

x^2-x-506 = 0

Use the quadratic formula to get the solutions x = 23 or x = -22.

I show the steps in solving here.

x is the number of people, so it has to be a positive whole number. That means we ignore x = -22

The only practical solution is x = 23.

That means the club has 23 members.

Notice how

x*(x-1) = 506

23*(23-1) = 506

23*22 = 506

506 = 506

So that confirms the answer.

RELATED QUESTIONS

In a club with 17 members, how many ways can the club elect a president and a treasurer? (answered by stanbon)
In a club with 17 members, how many ways can the club elect a president and a... (answered by jim_thompson5910)
A 40-member club will elect a president and elect a vice president. How many possible... (answered by Theo)
If the chamber of Commerce has 20 members, in how many ways can they elect a different... (answered by checkley77)
how many ways can a 30 member group elect a president and vice... (answered by addingup)
Suppose the 12 members of a club plan to elect a president, a vice-president and a... (answered by jorel555)
a club with 12 members wants to elect a president, a vice president, and a treasurer.... (answered by sudhanshu_kmr)
A club has 15 students. Anserw the follow. Show steps. a)How many different 3-member... (answered by ewatrrr)
How many ways can a president, vice-president, secretary, and treasurer be chosen from a... (answered by Alan3354)