When is the last time you coded in C/C++? What is the most lines of original C/C++ code you have personally written in one project? How confident are you in your ability to write C or C++ without a reference?

Yes this is a right question, but its answer depends on
individual, there is no direct associated answer.

Actually Interviewee want to judge candidate 's coding skills,
If He didn't write any code since past few months, or may be
since past few years.

based on the above interviewee can get the idea about the
coding confidence of candidate.