Think of an example of a math problem from a real world scenario that has no numerical solution

Question

Number of solutions pre algebra

Answer 1

How much do you love someone? Well, we can think of this as a math problem because we are talking about 'how much' yet we cannot determine a definite answer that involves a numerical solution ;)

Answer 2

enclosing a rectangular area of 100 square feet with only 5 feet of fencing.