Drexel dragonThe Math ForumDonate to the Math Forum

Ask Dr. Math - Questions and Answers from our Archives
_____________________________________________
Associated Topics || Dr. Math Home || Search Dr. Math
_____________________________________________

Total Membership


Date: 08/20/99 at 20:51:06
From: Geryca Foy
Subject: What is the correct answer?

At a country club 35 people play golf, 28 swim, and 24 play tennis. Of 
these people, 6 play golf and tennis only, 9 play golf and swim only, 
and 7 play tennis and swim only. 8 people do all three activities. How 
many members are there altogether?  

My teacher did the problem and the answer she gave us was 29, using a 
diagram. I don't understand how there can be fewer members in the 
country club than there are people playing golf.


Date: 08/20/99 at 22:36:08
From: Doctor Peterson
Subject: Re: What is the correct answer?

Hi, Geryca.

You probably copied the answer incorrectly. It should be 49, which 
makes more sense. Here's the diagram:

            ...........  ***********
 golf   ....         **....         ****   swim
      ..           **      ..           **
     .            *    9     .            *
    .    (12)    *            .     (4)    *
    .            * -----------.            *
    .          --*-           .---         *
    .        --  *     8      .   --       *
     .      -     *          .      -     *
      ..   -   6   **      ..   7    -  **
        ...-         **....         *-**
           -...........  *********** -
           -                         -
            -          (3)          -
             --                   --
               ----           ----
                   -----------

                      tennis

The numbers in parentheses were filled in last, by subtracting the 
given numbers from the total for each activity. Then I just added the 
numbers up.

- Doctor Peterson, The Math Forum
  http://mathforum.org/dr.math/   
    
Associated Topics:
High School Discrete Mathematics
High School Sets

Search the Dr. Math Library:


Find items containing (put spaces between keywords):
 
Click only once for faster results:

[ Choose "whole words" when searching for a word like age.]

all keywords, in any order at least one, that exact phrase
parts of words whole words

Submit your own question to Dr. Math

[Privacy Policy] [Terms of Use]

_____________________________________
Math Forum Home || Math Library || Quick Reference || Math Forum Search
_____________________________________

Ask Dr. MathTM
© 1994-2013 The Math Forum
http://mathforum.org/dr.math/