Hmm if they want an answer from the scientific modes of a electronic calc then I would suggest to them they are holding on too tight and should think about turning in their wings
But if you insist...eyballing it I would say you crossed track 10 nm back giving a track error of 12 deg (2 off in 10). 2 off with 20 to run is 6 deg closing angle. Turnleft 18deg.
But we're talking < 1/2nm one way or tother here
Reminds me of ATPL Nav. It took 30 minutes of button bashing to get the 'right answer' to the PNR question.
Given this is the private flying thread I'll let you in on a secret...in real life it takes 2 minutes.
Chuck.