Question

Find the number of terms in the geometric progression 6, 12, 24, ..., 1536

Answer 1

Hi ,

6 , 12 , 24 , ..... , 1536 are in G.P

First term = a = 6

Common ratio = r = a2 / a1

r = 12/2

r = 6

nth term = an = ar^n-1

6 × 2^ n- 1 = 1536

6 × ( 2^n / 2 ) = 1536

3 × 2^n = 1536

2^n = 1536/3

2^n = 512

2^n = 2^9

n = 9

[ If a^m = a^n then m = n ]

Therefore ,

9 th term in G.P = 1536

I hope this helps you.

:)

Answer 2

ANSWER
.........


1ST TERM = a = 6

Common ratio = r = a2 / a1

R = 12 / 6
R = 6
6* 2 ^N - 1
6 *2 ^N/ 2 = 1536
..........



2^n = 1536/3

2^n = 512

2^n = 2^9

n = 9
...................

THAT IS WHY
$= = = = = = = = =$


9 th term in G.P = 1536