Please check if this helps.

docx: application/vnd.openxmlformats-officedocument.wordprocessingml.document

doc: application/msword

jpg: image/jpeg

png: image/png

xlsx: application/xlsx OR application/vnd.openxmlformats-officedocument.spreadsheetml.sheet

xls: application/vnd.ms-excel

pptx: application/vnd.openxmlformats-officedocument.presentationml.presentation

pdf: application/pdf