The 5th term of a G.P. is 243 and the sum of its first five terms is 363.
a. (i) Show that the common ratio r satisfies ar4=243, where a is the first term.
b. (ii) Determine the exact values of a and r.
c. (iii) Find the smallest positive integer n for which the nth term of this G.P. exceeds 59000.