#1 adding 147 to 47 equals 171. If Liam and Sidney are 124 miles apart and Troy is 47 more miles apart from Liam then it is adding the distance already given to the distance he is from Sidney since she is in the middle.
#2 from 40 to 20 to 20 to 10 from 10 to 5 from 5 to 2.5 from 2.5 to 1.25. Just divide by 2 till it is 2 or less than feet.
