So I had a similar experience with your prompt (on the f16 model). But I do think that, at this size, prompting differences make a bigger impact. I had this experience trying to get it to list entities. It kept trying to give me a bulleted list and I was trying to coerce it into some sort of structured output. When I finally just said "give me a bulleted list and nothing else" the success rate went from around 0-0.1 to 0.8+.

In this case, I changed the prompt to:

---

Tallest mountains (in order):

```

- Mount Everest

- Mount K2

- Mount Sahel

- Mount Fuji

- Mount McKinley

```

What is the second tallest mountain?

---

Suddenly, it got the answer right 95+% of the time