Two hundred fence posts are to be placed into the ground in a straight line, 3m apart. The fence posts are stacked in a pile along this same line, 3m from the position of the first post to be put in. Maybell is going to put in the posts one at a time in order, and each post she puts in is farther away from the pile. Maybell can only carry one post at a time, and so she always walks back to the pile to get the next post. If Maybell starts at the pile, how many kilometers mush she walk to finish the job?
First post at 0 second one requaires walking 3m and back = 6 m
third one is 12 m then 18 m
Arithmetic sequence d = s a1 = 0 a 200 = 0 + 6(199) = 1194
Sum = 200 (0+ 1194)/2 = 119400 meters = 119.4 km
yikes!