<span>1. Draw a set of railroad tracks such that the lengths of horizontal ties form a geometric sequence.
Answer:
A geometric sequence is a sequence whose terms keep a constant ratio, for example, 1, 2, 4, 8. 16, ... As you see the ratio is between a term and the previous one is 2/1 = 4/2 = 8/4 = 16/8 = 2.
With that in mind, you can draw a sequence of rail roads with lenghts 1, 2, 4, 8, 16 ,...