11 percent have
not used a computer to write reports, so 100-11=89 percent have used a computer to write reports.
95 percent have used a computer for one purpose, so 100-95=5 percent have
not played games AND
not written reports.
7 percent have
not used a computer to play games, so 7-5=2 percent have
not played games AND have written reports.
This leaves us with 89-2=87 percent who have used a computer to play games AND to write reports.
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File comment: Matrix of students
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