Given that 6,9,13 1/2,20 1/4 form a sequence of numbers, find the sum of it 13 term

Answer 1

clearly, a=6, r=3/2

S13 = a(r^13-1)/(r-1) = 6((3/2)^13 - 1)/(3/2 - 1) = 4758393/2048