Question 490147
In 1 hour Kate has traveled 80 km
That is the time when Juan leaves


every hour Kate is ahead by 8 km  (80-72) 

They have to be 98 km apart .
already she is 80 km apart when Juan leaves
98-80= 18 km 
how much time will she take to be ahead by 18 km

18/8 = 2.25 hours