Principles of Flight Exam
WOW ... that looks good to me .... but then I know nothing about this subject .... "I learn it from a booook".
The ITW Lecture Notes (in which I found the exam paper) call it "Form" drag rather than Profile drag ... but I won't dock you any marks for that ... unless others feel I should.
There is a second part to the question which is:
"Give reasonable values for:
(a) The Lift / Drag ratio of a wing
(b) The Lift / Drag ratio of a complete aircraft"
..... so over to you
Regards
Pete