Gregor Mendel didn't solve a single, specific problem in the way we might think of a scientific breakthrough. Instead, he laid the foundation for our understanding of how traits are passed down from parents to offspring.

Here's a breakdown of what Mendel did:

* He studied inheritance patterns: Mendel experimented with pea plants, meticulously tracking traits like flower color and seed shape over generations.

* He discovered the laws of inheritance: Based on his observations, Mendel formulated the fundamental laws of inheritance, which include the Law of Segregation and the Law of Independent Assortment. These laws explain how genes, the units of inheritance, are passed down from parents to offspring.

* He established a framework for genetics: Mendel's work provided the basis for the modern field of genetics, which studies heredity and variation in living organisms.

So, while Mendel didn't solve a specific problem in the traditional sense, his work revolutionized our understanding of how traits are passed on and laid the groundwork for future discoveries in genetics.