Name the relationship

Aword processing program requires a 7- digit registration code made up of the digits 1,2,4,5,6,7 and 9 each number has to be used and no number can be used mor than once how many codes are possible

Im so bad at fractions they are not my best math thing to work on

Renee hiked for 6 3 /4 miles. after resting, renee hiked back along the same route for 5 1 /4 miles. how many more miles does renee need to hike to return to the place where she started? represent your answer as a simplified mixed number, if necessary.