A sheet of plywood is 5/8 inches thick. How tall is the stack of 21 sheets?
To find the total height of the stack of 21 sheets, we need to multiply the thickness of one sheet by the number of sheets.
Thickness of one sheet = 5/8 inches
Number of sheets = 21
Height of the stack = (5/8) * 21 = 105/8 = 13.125 inches
Therefore, the stack of 21 sheets is 13.125 inches tall.