Math Problem 3: Two Times Two is Five
Start with the obviously true equation 4/4 = 5/5. Taking out the common factor from each side, we get 4 * (1/1) = 5 * (1/1) which is the same as (2 * 2) * (1/1) = 5 * (1/1), and finally, since 1/1 is obviously 1, the conclusion is 2 * 2 = 5.
Where is the logical fallacy?
Find the first incorrect equation. The problem must have been introduced at that step.
The error was in "taking out the common factor", which is not at all what was actually done mathematically. Note, for example, that 4 * (1/1) does not equal 4/4.