answer:As I thought about the solution to the first problem I realized that it’s exactly the way to resolve the second one. Take the difference between five times the lowest number in the set (5x), and the highest number in the set (X’). If 5x – X’ is a positive number, then you’ve proven the concept. This is exactly how I’d resolve the second instance. Multiply the age of the youngest person in the room by 5, and see if that’s a larger number than the age of the oldest person. In context it might be simpler, because it’s probably easier to “see” if you have, for example, a college senior as the youngest person in the room (probably at least 20 or 21 years old), then you’d need a 100-year-old-plus to exceed the 5x value. And that might be simple enough to see if no one appears to even be in their 80s. Problem 3 is a completely different problem, because there you have to work with much smaller numbers. “No number greater than the square of any other number” means you will be working in the range of -1 to 1.