Question

. Number of terms in the G.P 5,20, 80, 320 ...........20480
a) 5
b) 6
c) 8
d) 7

Answer 1

Answer:

d. 7

Step-by-step explanation:

Given, 5, 20, 80...

Common ratio, r = 20 / 5 = 4 ; 80 / 20 = 4.

Last term or nth term of GP = ar ^ (n-1)

20480 = 5 × (4 ^n-1)

4^n-1 = 20480 /5

4^n-1 = 4096

4^n-1 = 2^8

So, comparing the power,

Thus, n - 1 = 8

Or, n = 7

Number of terms = 7

Mark me brainliest :)))

Answer 2

Answer:

hello army...............