Without Blue or Brown

 

The Problem

There are 30 students in a class. Eleven have blue eyes. Fifteen have brown hair. Three students have both blue eyes and brown hair. How many students have neither blue eyes or brown hair?

(Source: Jon Basden)

 


Disclaimer!!!: I was looking over someone's website and wanted to give my version of the answer...why don't you figure out which is right and why!!! (I will not say who gave which answer...)




Solution #1
The solution to this problem can best be displayed in a venn diagram. I used Microsoft Word to draw a venn diagram and to plug in the information from the problem. The problem states that 11 students have blue eyes, 15 students have brown hair, and 3 students have both. The total of those three categories accounts for 29 students. We know there are 30 students, this leaves 1 student without blue eyes or brown hair. See the venn diagram below:

 

Solution #2

The solution to this problem can best be displayed in a venn diagram. I used Microsoft Word to draw a venn diagram and to plug in the information from the problem. The problem states that 11 students have blue eyes, 15 students have brown hair, and 3 students have both. The total of those three categories accounts for 23 students. We know there are 30 students, this leaves 4 students without blue eyes or brown hair. See the venn diagram below:

Solution #3

Which solution, if any, is correct? What is your solution #3???

 

 

 


Go to www.venndiagram.com to create venn diagrams.


Return