Expert: Paul Klarreich - 8/10/2011

Question
How to solve this? It's about solving problems in quadratic equation. Here's the problem : The members of a mathematics club agreed to contribute equally to provide a fund of P240. If there had been 3 more members, each would have paid P4 less than the original agreement. How many members were present in the club?
I really need the answer as soon as possible. Thank you!

Answer
Questioner:Bobby
Country:Nueva Ecija, Philippines

Category:Advanced Math

Private:No
Subject:Intermediate algebra
Question:
How to solve this? It's about solving problems in quadratic equation. Here's the problem : The members of a mathematics club agreed to contribute equally to provide a fund of P240. If there had been 3 more members, each would have paid P4 less than the original agreement. How many members were present in the club?
I really need the answer as soon as possible. Thank you!

Start with:

Let N = the original number of members.
   N+3 = the new ................

Then:

240/N = the original contribution.
240/N - 4  = the new ..........
And:

240/(N + 3) = 240/N - 4   -- which is NOT the same as 240/(N-4)

or:
240    240  
----- = ---- - 4
N + 3    N

Multiply out, by  N(N + 3)

240N = 240(N + 3) - 4N(N + 3)

You should be able to finish up.