This is a test of your intuition. Do not try to solve this but do use your intuition to arrive at the quickest answer.
from
“Thinking fast and slow” a fantastic book by Pulitzer prize winner, Daniel Kahneman. The concepts in this book have implications for how we structure work processes so that our brains function they way we need them to to prevent safety transgressions.
Safety Dog's Blog 
The answer is 5 cents 🙂