In a geometric sequence, a4=54 and a7=1458. What is the 12th term?

a. 5,616

b. 354,294

c. 14,350,365

d. 234,812,358

A7 / a4 = r^ (7-4) = r^3 where r = common ratio

so r^3 = 1458 / 54 = 27

r = 3

12th term = a7 * r^5 = 1458 * 3^5 = 354,294

Note r could also be - 3 but not in this case because 12th term is positive

Its b