2/3 of the distance is 0.666 = 66.6% of the distance...rounds to 67%...so Martha has traveled 67% of the distance. While Jackson has traveled 78% of the distance.
So ur untrue statement would be : Martha has a shorter distance left to go to the Aunt's house then Jackson......because Martha has traveled 67% and Jackson has traveled 78%, so Martha would have a longer distance to go then Jackson