please answer these two questions. i think they would be easy for some and please make sure they are correct. thats all i ask :( <33

Answer:
17. Tallest post is 3 feet tall. Each of the next tallest post is 5/6 the last.
a. Height of the shortest post: 3 x 5/6 x 5/6 x 5/6 x 5/6
b. 625/432 feet to be exact.
18. a. Nicole ran: 4 : 2 : 2 : 2
b. Half a mile