Question

In a woodworking you are planing boards to make shelves. The planer is set to remove 1/16 inch from a board on each pass the board makes through the planer. If a board starts out at 3/4 inch thick, how many times will you need to send it through the planer to get it down to 5/8 inch?

Answer 1

Material removed per pass = 1/16 in
Initial thickness = 3/4 in
Final thickness = 5/8 in

If x is the number of passes,
The material removed = (1/16)x in.
Therefore,
3/4 - (1/16)x = 5/8
3/4 - x/16 = 5/8
x/16 = 3/4 - 5/8 = 1/8
x = 16*1/8 = 2

Therefore, the board will be passed through the plane twice.