Answer:
See explanation below.
Step-by-step explanation:
We have the statement that says that the sum of two two-digit numbers is a three digit number.
To prove that this statement is false, we only need to give a counterexample. This means that we have to find two two-digit numbers that does not sum a three digit number.
Let's take 11 and 12, if we sum them we have: 11 + 12 = 23.
23 is clearly a two digit number.
Therefore, the sum of two two-digit numbers is not a three digit number.