trying to make all faq answers 18 pt text

Hi,
I have support access on for: http://bnmprojects.info/justgrow

The site uses tinymce advanced and ultimate faq. on this page i’m trying to make all the faq answers 18 pt text.

http://bnmprojects.info/justgrow/faqs-2/

The option is available on other pages but not on this page.