Your question is Weighing Puzzle With QA Mindset. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
You have eight pennies all of the same size, and a classic balance scale. 7 of them weigh the same, and one of them weighs slightly more. how do you find which one weighs more.