Answer:
1.
1 1/15
2.
1 7/15
3.
I think that the sister rode farther by 2/5
reason:
(the sister) 2/3 mile+4/5 mile=1 7/15
(you) 2/3 mile+2/5=1 1/15
1 7/15-1 1/15= 2/5(according to a website I used)
