What is the length of a rectangle with width 16 in and area 104in ^2

The length and width of a rectangle are consecutive even integers the area of the rectangle is 120 squares units what are the length and width of the rectangle

Carl's candies has determined that a candy bar measuring 3 inches long has a z-score of +1 and a candy bar measuring 3.75 inches long has a z-score of +2. what is the standard deviation of the length of candy bars produced at carl's candies?

Idon't get undoing if its pass adding and subtracting so can someone ? x-2 over 5 = 18