The common ratio of a geometric series

Question

is 1/3
and the sum of the first 5 terms is 121.
a) What is the value of the first term?
b) Write the first 5 terms of the series.

Answer 1

S=t*(1 - r^n)/(1 - r)

121=t*(1 - 1/3^5)/(1 - 1/3)
t1 = 81

Answer 2

81, 27, 9, 3, 1
sum = 121, yep, sure enough :)