# Rolling dice

**Discrete Mathematics**Level 3

Two dice are rolled simultaneously.

This is done repeatedly until **at least** one die shows a 6, at which point the game is finished.

What is the probability that both dice show a 6 on the last roll?

The probability can be expressed as \(\dfrac ab\) for co-prime positive integers \(a\) and \(b\), find the value of \(a+b\).