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
_____________________________________________

Venn Diagram: Goops, Gorps, Gorgs

Date: 09/19/2002 at 00:03:47
From: Regina
Subject: Brain teaser

Every Goop is a Gorp. Half of all Gorgs are Gorps. Half of all Gorps 
are Goops. There are 40 Gorgs and 30 Goops. No Gorg is a Goop. How 
many Gorps are neither Goops nor Gorgs?

Is the answer zero?


Date: 09/19/2002 at 12:25:28
From: Doctor Peterson
Subject: Re: Brain teaser

Hi, Regina.

Draw a circle representing the Goops. Draw another circle around this 
for the Gorps; we put the Goops entirely inside the Gorps because all 
Goops are Gorps.

Now notice that no Gorgs are Goops. Where should we draw the circle 
for the Gorgs?

Now you have a Venn diagram for the problem, and can start filling in 
numbers, using the given numbers and ratios.

For fun, here's my version:

    +---------------------+
    | gorps               |
    | +-------+   +-------|-------+
    | | goops |   |     gorgs     | 40
    | |  30   |   | 20    |    20 |
    | +-------+   +-------|-------+
    |           10        |
    +---------------------+

If you have any further questions, feel free to write back.

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

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/