The sum of three consecutive number is 90. what is the smallest of the three numbers ?

Based on what i know about mean, this doesn't add up.

Mary works for a company that ships packages and must measure the size of each box that needs to be shipped. mary measures a box and finds the length is 7 inches, the width is 14 inches, and the height is 15 inches. what is the volume of the box? [type your answer as a number.]

What expression is equivalent to (2x-1)(x-3)?