Answer: 21 more miles
Step-by-step explanation:
Gabriel ran
Logan ran

now we change to an improper fraction
Gabriel

Logan

now we find their LCM
LCM of 5 and 4 is 20
we convert the fraction into a number in order to know the miles taken by the two boys
Gabriel
×20 = 5÷20
=4
6×4=24miles
Logan
×20=4÷20
=5
9×5=45miles
how long Logan took more than Gabriel
45-24=21miles more