Introduction: (In Your Notebook) Several students are surveyed about whether they prefer writing with a pen or a pencil and they are
also asked whether they prefer lined paper or unlined paper. Some of the results are:
• The survey included 100 different students.
• 40 students said they prefer using pen more than pencil.
• 45 students said they prefer using unlined paper more than lined paper.
• 10 students said they prefer lined paper and pen.
• 45 students said they prefer pencil and lined paper.
How could we determine the following?
1. How many students prefer using pencil more than pen? 60
2. How many students prefer using pen and unlined paper? 40
3. How many students prefer using pencil and unlined paper? 15