Answer:
1.4 hours
Step-by-step explanation:
Runner A:
Speed = 8.1 mph
Time, = t
Runner B :
Speed = 6.3 mph
Time, = t
Distance apart = 20.16 miles
Distance = speed * time
Distance of Runner A + Distance of runner B = distance apart
8.1t + 6.3t = 20.16
14.4t = 20.16
t = 20.16 / 14.4
t = 1.4 hours
Number of hours, t = 1.4 hours
