Write permission has no effect in the absence of execute permission, so this mode behaves just like the above mode. However, files can't be created or deleted. Access means that you can view, change, or execute the files as permitted by the files' own permissions. Files can't be created or deleted. You can't delete a file from a read-only directory, even if you're allowed to make changes to the file.
File permissions have nothing to do with deleting files.
This also means that if you own a directory you can always delete files from it, even if those files belong to root. If you have execute permissions to a directory, file permissions for that directory become relevant. Finally, permission to change permissions on a file or directory is not affected by the permissions of that file or directory. Rather, you can always change the permissions on files or directories that you own, but not on files owned by someone else, as long as you are permitted access to the file. This means that you can't permanently remove permissions from yourself because you can always give them back.