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11 grade maths others

Which term of the G.P. 2, 8, 32,… is 131072?

Profile image of Aniket Singh
1 Year agoGrade
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1 Answer

Profile image of Askiitians Tutor Team
1 Year ago

To find which term of the geometric progression (G.P.) 2, 8, 32,... is 131072, we will use the formula for the nth term of a G.P.:

T_n = a * r^(n-1)

Where:

T_n is the nth term,
a is the first term,
r is the common ratio,
n is the term number.
In the given G.P., we have:

a = 2 (the first term),
r = 8 / 2 = 4 (the common ratio).
We need to find the value of n when T_n = 131072.

Using the formula: 131072 = 2 * 4^(n-1)

Now, divide both sides by 2: 131072 / 2 = 4^(n-1) 65536 = 4^(n-1)

Next, express 65536 as a power of 4: 65536 = 4^8

Thus, we have: 4^(n-1) = 4^8

Since the bases are the same, we can equate the exponents: n - 1 = 8

Solving for n: n = 9

Therefore, the 9th term of the G.P. is 131072.