Answer: The right answer is 2
Step-by-step explanation:
T1; a = 0.3 ------------ (I)
T8; ar^7 = 38.4 ------------ (ii)
Substituting for 'a' in the second equation, we have;
0.3r^7 = 38.4
0.3r^7 = 38.4
Divide both sides by 0.3
r^7 = 38.4/0.3
r^7 = 128
r = (128)^1/7
r = 2