A Multiple of Seven
A fair six-sided die is rolled repeatedly and a running total of all rolls is kept. You stop as soon as the running total is a positive multiple of 7. What is the expected number of rolls? Give an exact number.
Related problems & prerequisites
Worth solving first
- Pólya's Urn 5.0/10
- The Lost Boarding Pass 5.0/10
- One Ace Apiece 5.0/10
Source: Original problem written for AxiomIQ.