The rhumb line distance from A at 57N 12*30' W to B at 57N 167*30E is :
a. 3690 nm
b. 5882 nm <--- answer given
c. 10800 nm
d. 9057 nm
Looking at the longitude it is exactly 180 degrees apart which means you could travel a line of constant direction (a rhumb line) North up to the N pole and then South to 57N. That would then employ GC techniques eg. 1 degree = 60 NM
90 degrees - 57 degrees = 33 degrees x 2 = 66 degrees
66 degrees x 60 = 3960 NM.
Otherwise it is Departure formula
Departure in NM = dlong (in min) x cos mlat
Departure in NM = 180 x 60 x cos 57
Departure in NM = 180 x 60 x 0.545
Departure in NM = 5882
I would query this question, the answer of hose given to chose is therefore 5882. But can you see something correct in what I write about over the pole as an option?