Answer:
Option 4 (a1 = 1, r = 3)
Step-by-step explanation:
a1 = 1
r = 3
3 = 3(1)
9 = 3(3)
27 = 3(9)
81 = 3(27)
'a1' is the first number in a sequence
'r' is the common ratio
Thus, your answer would be d.
a1 = 1 and r = 3
