Question 505416
Your teacher gives you two standard six-sided dice.  The teacher asks you to roll the dice and add (sum) the two numbers on the dice.  How many times must you toss the dice to be sure that you repeat at least one sum from your previous rolls?  By the way, the answer is not two.  
---
The sums range from 2 to 12.
---
12 rolls will assure you of a repeat.
===============
Cheers,
Stan H.