SOLUTION: Upon examining the contents of 38 backpacks, it was found that 23 contained a black pen, 27 contained a blue pen, and 21 contained a pencil, 15 contained both a black pen and a bl

Question 462347: Upon examining the contents of 38 backpacks, it was found that 23 contained a black pen, 27 contained a blue pen, and 21 contained a pencil, 15 contained both a black pen and a blue pen, 12 contained both a black pen and a pencil, 18 contained both a blue pen and a pencil, and 10 contained all three items. How many backpacks contained exactly two of the three writing instruments?
Answer by edjones(8007) (Show Source): You can put this solution on YOUR website!
Make a 3 circle Venn diagram to understand this.
2+5+8=15 contained exactly two of the three writing instruments.
.
Ed
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