The total cost of toilet paper is 10 * $1.5 = $<<10*1.5=15>>15
The total cost of paper towels is 7 * $2 = $<<7*2=14>>14
The total cost of tissues is $35 - $15 - $14 = $<<35-15-14=6>>6
The cost of one box of tissues is $6 / 3 = $<<6/3=2>>2.
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