33 How to delete files with some extension inside specific folder over tree?

thanks to Anderson M. Gomes http://unix.stackexchange.com/questions/270071/how-to-delete-all-files-with-specific-extension-in-specific-named-folders-in-lar

Here is the code

#to check 
$ find /path/to/source -type d -name 'rules' -exec find '{}' -mindepth 1 -maxdepth 1 -type f -iname '*.pdf' -print ';' 
 
#to delete 
$ find /path/to/source -type d -name 'rules' -exec find '{}' -mindepth 1 -maxdepth 1 -type f -iname '*.pdf' -print -delete ';'