A jogger ran #1/3# mile on day 1, and #2/3# mile on day 2, and 1#1/3# miles on day 3, and 2#2/3# miles on day 4, and this pattern continued for 3 more days. What expression represents the total distance the jogger ran?

1 Answer
Apr 16, 2018

A.

Explanation:

#Sigma1/3(2)^(d-1)# is the only rule that seems to work, the seven on the top indicates the integer to which the sum must be carried out, starting at #d=1# using this rule.

This #Sigma1/3(2)^(d-1)# is the only answer choice that works for Day 1 even, as the jogger needs to have run #1/3# mile on day #1#:
#Sigma1/3(2)^(d-1)= 1/3(2)^(1-1)= 1/3(2)^(0)= 1/3(1)= 1/3 # miles for day 1