Not suggesting you should attempt this method for exams but just for practical purposes:
Max Drift (MD) = (WV X 60) / TAS
= (36 x 60) / 120 (Note the convenience of 36 x 60 and 120 - quite easy to do in your head)
= 18 degrees, when applied 90 degrees off track
15 degrees off track = 1/4 of MD
30 degrees off track = 1/2 of MD
45 degrees off track = 3/4 of MD
60 degrees off track = FULL MD
Therefore, 85 degrees track against 55 degrees wind direction = 30 degrees = 1/2 MD
= 9 degrees, turning into wind = True Heading of 85 - 9 = 76 degrees
Add Magnetic Variation = 76 + 7 = 83 degrees Magnetic
Took me 30 seconds (after 4 x bottles of Magners) and I'm no genius - mind you, the numbers in the question helped.
CPL instructor used to b*ll*ck me every time I picked up the CRP - "You don't need that. Max Drift, boy, Max Drift"