Answer:
Adam's average speed is 42 mph
Explanation:
Let Adam's average speed be x
Krystal travelled 28 mph faster than Adam
Therefore, Krystal's average speed is (x + 28) mph
Krystal left 2 hours after Adam and caught up with him after 3 hours
Total time taken for Adam to travel a distance d m = 2 hours + 3 hours = 5 hours
Time taken for Krystal to travel the same distance (catch up with him) = 3 hours
Average speed = distance/time
distance = average speed × time
Since both travelled the same distance
5(x) = 3(x+28)
5x = 3x + 84
5x - 3x = 84
2x = 84
x = 84/2 = 42 mph
Adam's average speed is 42 mph
