To open an image in photoshop
Go to file, open
Find your testwork folder
Select your image
To save the image, change its name or extension
Go to File, save as
Find your testwork folder
Rename your file exactly the same as your exam paper including spelling and capitalization
You can change the extension for example p n g
Then press save
If you edited or added layers to the image
You can save it using the photoshop extension p s d
Go to file, Save as
Find your testwork folder
Rename your file