So 7 is the common ratio.
next question is
a1 = 3; an= an-1 x 7
question after that is
common ratio = 7
Common ratio = 7
If a sequence is a geometric sequence, given in the form of a, a(r), a(r)² ..........
common ratio of the given sequence will be =
Now we apply this rule in the given sequence 3, 21, 147,.............
Then the common ratio r =
r = 7
This can be applied in 2nd and 3rd term but common ratio will remain same as 7.
Therefore, common ratio = 7 is the answer.
r = 7
The common ratio r of a geometric sequence is
r = = , that is
r = = = 7
the first 5 right here the next 5 i will upload as separate question