Current postal regulations state that no package may be sent if its combined length, width, and height exceed 70 in. What are the possible dimensions of a box to be mailed with equal height and width if the length is three times the height?

Question

Current postal regulations state that no package may be sent if its combined length, width, and height exceed 70 in. What are the possible dimensions of a box to be mailed with equal height and width if the length is three times the height? ​

Quizplus · Accepted Answer

Let the height be x. Then, according to the given conditions, the length must be 3x and the width must also be x. Therefore, the combined length, width, and height would be 5x. In order for the package to be mailable, 5x must be less than or equal to 70. Thus, x must be less than or equal to 14. Using this information, we can see that the height and width must each be 14 in. or less and the length must be 3 times the height which puts it at 42 in. Therefore, the correct answer is (C).

Current Postal Regulations State That No Package May Be Sent