See question in image and show workings
Note : 1 nautical mile = 1.86km

Answer:
a)
AB is on the latitude 30°N.
Find AB:
BC is along longitude 35°W
Find BC:
Total distance traveled:
Convert the distance to nautical miles:
12067.92/1.86 = 6488.13 nautical miles
b)
Find the average speed:
Note. This is unrealistically high speed for a ship, this must be a plane or the time given wrong.