A ball is dropped from a height of 125m and rebounds to 60% of the height from which it falls after each bounce.
a. (i) Express the height reached after the nth bounce in the form of a sequence and state the common ratio.
b. (ii) Calculate the height reached after the 6th bounce.
c. (iii) Determine the smallest integer n for which the height after the nth bounce is less than 5m. Show all working steps.