Use this topic to ask your questions about the PennyLane Challenge: Noisy QAOA.

I am not sure why only my first public test set and all private tests work. My step variable ‘steps = 250’

Running submission…

```
Running on public test set
Test 1 of 2 passed! ✅
Input: [1, 0.003]
Expected output: 0.1307
Solution output: 0.13011411675043585
Test 2 of 2 failed! 🚫
Input: [2,0.005]
Expected output: 0.4875
Solution output: 0.46662334164166946
Failure message: Assertion Error.
Running on private test set
Success! 🎉
```

I changed it to 249 and it worked!

I am a bit confused. When I look at the tutorial, the depth of `qaoa_larer`

is used in the cost function, but in the challenge problem, it only appears as an argument of the `approximation_ratio`

function. Should the cost function be defined in `approximation_ratio`

instead of `qaoa_circuit`

?

Hey @Mayu! Welcome back

In the “Intro to QAOA” tutorial, `depth`

was just taken to be a fixed value (`depth = 2`

). In the challenge, `qaoa_depth`

(same purpose as `depth`

in the tutorial) is used within `approximation_ratio`

to create parameters for the `qaoa_circuit`

(they need to be optimized). Let me know if that clears things up!

Hi, @isaacdevlugt ! I’ve misunderstood! I thought the qml.layer function would repeat the same parameter for the number of depths. Thanks for your hint!

Awesome! Glad I could help