Welcome to your interview.
The question is on your right: Balance Scale Counterfeit Coin. Take a moment with it first.
Talk your thinking through with me if you like - when you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes). Discussion and graded submissions share your five interviewer interactions, so spend them well.
There are 8 identical-looking coins, but one is counterfeit and lighter than the rest. What is the minimum number of weighings needed on a balance scale to find the counterfeit coin?