We are really cycling through the mount commands... I wonder if the drive was just not mounted in the first place... 
mount -o rw /dev/sda3 /mnt
sudo chown raaghu:raaghu '/media/raaghu/dev/sda3'
We are really cycling through the mount commands... I wonder if the drive was just not mounted in the first place... 
mount -o rw /dev/sda3 /mnt
sudo chown raaghu:raaghu '/media/raaghu/dev/sda3'
I am really sorry for that 
Initially it was mounted. When I changed the permission everything started messing up.
I am totally a newbie to Linux. So, please bear with me 

I am also sorry; I am in the habit of using sudo -i so when I type a command for others, I sometimes forget to include sudo (bad habit):
sudo mount -o rw /dev/sda3 /mnt
I may give a lightning fast response, but I am a little slow 
Hey not a prob
It is great that you are helping me out 
Don't worry I am the slowest 
By the way, it looks like this step worked! Please check.

Looks good- can you test if you have full access on that drive?
If not, run the sudo chown raaghu:raaghu '/media/raaghu/dev/sda3' again...
No access yet i guess.

Let's see lsblk again and see what that says...
Sure.

Well, it is referring to it as /mnt/a9d058e3-c98d-49ba-80b5-51a2fb3537b8, so let's try doing what it wants us to do...
sudo chown raaghu:raaghu '/mnt/a9d058e3-c98d-49ba-80b5-51a2fb3537b8/raaghu/dev/sda3'
I didn't work I guess.

Am I too sleep dep for the helpdesk right now....
sudo chown raaghu:raaghu '/mnt/a9d058e3-c98d-49ba-80b5-51a2fb3537b8/dev/sda3'
Please don't mind!

Maybe I am too hung up on thinking of the /dev/sda3...
sudo chown raaghu:raaghu '/mnt/a9d058e3-c98d-49ba-80b5-51a2fb3537b'
This should be easy - I have solved this in one post a dozen times. I am stumped.
Oh!! I normally I encounter special problems!
Is there a way out?
I am sure there is and that it will be easy.
I seem to be failing you right now.
What is the output of
sudo nano /etc/fstab
Well, I see where I went wrong in the /mnt/a9d.... that would try to mount the mount point, not the drive. That makes sense.
However, that /dev/sda3 is not responding is what has me stumped.
Are you able to see the files in your File Manager and access them? But just cannot write within?
Yes, it was the case earlier. That is, before we started trying to solve. But now it is not the case. When I am trying to open Partition D, I get the following error.
