Answer:
32.8 miles
Step-by-step explanation:
The total time travelled by rider A is 2 hours. If his speed was 12 mph, the distance travelled is 2 * 12 = 24 miles.
The total time travelled by rider A is 3 hours and 30 minutes (so 3.5 hours). If his speed was 9 mph, the distance travelled is 3.5 * 9 = 31.5 miles.
The angle that they make, as rider A was in the direction N 47 E and the rider B was in the direction S 62 E, is equal to 180 - 47 - 62 = 71°
With these values (two distances and a angle between then, we can use law of cosines to find the distance between the bicyclists:
c^2 = a^2 + b^2 - 2ab*cos(angle)
c^2 = 24^2 + 31.5^2 - 2*24*31.5*cos(71)
c^2 = 1075.99
c = 32.8 miles