1 answer
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The total surface area needed for the box can be calculated by 2lw + 2lh + 2wh, where l = 10 inches, w = 9 inches, and h = 7 inches.
Total surface area = 2(10)(9) + 2(10)(7) + 2(9)(7)
Total surface area = 180 + 140 + 126
Total surface area = 446 in²
Since Charisse purchased 500 in² of cardboard, the amount left over would be:
500 - 446 = 54 in²
Therefore, the correct answer is 54 in².