Nothing, because your answer is incorrect! If you require the pieces to be exactly 2m long without allowing for any margin of error, then there isn't a saw tha

Nothing, because your answer is incorrect! If you require the pieces to be exactly 2m long without allowing for any margin of error, then there isn't a saw that will cut that accurately, so the answer is 0, not 2. If you allow for the accuracy of the saw, then the answer is 3 since any saw can cut within its own accuracy. :-)