I just installed fresh Ubuntu 20.04 and try to install CUDA 11.7 i found debian(local) command to install CUDA 11.7

wget https://developer.download.nvidia.com/compute/cuda/repos/ubuntu2004/x86_64/cuda- 
ubuntu2004.pin
sudo mv cuda-ubuntu2004.pin /etc/apt/preferences.d/cuda-repository-pin-600
wget https://developer.download.nvidia.com/compute/cuda/11.7.0/local_installers/cuda-        
repo-ubuntu2004-11-7-local_11.7.0-515.43.04-1_amd64.deb
sudo dpkg -i cuda-repo-ubuntu2004-11-7-local_11.7.0-515.43.04-1_amd64.deb
sudo cp /var/cuda-repo-ubuntu2004-11-7-local/cuda-*-keyring.gpg /usr/share/keyrings/
sudo apt-get update
sudo apt-get -y install cuda

But while running sudo apt-get -y install cuda it says

Errors were encountered while processing:

nvidia-dkms-515

cuda-drivers-515

cuda-drivers

nvidia-driver-515

cuda-runtime-11-7

cuda-demo-suite-11-7

cuda-11-7

cuda

E: Sub-process /usr/bin/dpkg returned an error code (1)

I tried many ways but no solution

uname -r
6.5.0-35-generic

spci | grep -i nvidia
08:00.0 VGA compatible controller: NVIDIA Corporation GA102 [GeForce RTX 3080] (rev a1)
08:00.1 Audio device: NVIDIA Corporation GA102 High Definition Audio Controller (rev a1)


nvidia-smi
NVIDIA-SMI has failed because it couldn't communicate with the NVIDIA driver. Make 
sure that the latest NVIDIA driver is installed and running.

I am able to install cude 12.X
But I need 11.7 or less than 11.7 to perform specific task.