Mathematics
The fourth term of a G.P. is eight times its seventh term. The fifth term of then G.P. is , then find its 12th term.
GP
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Answer
By formula,
an = arn - 1
Given,
The fourth term of a G.P. is eight times its seventh term.
a4 = 8a7
ar4 - 1 = 8ar7 - 1
ar3 = 8ar6
r = .
Given,
Fifth term =
12th term :
a12 = ar12 - 1
= ar11
= .
Hence, 12th term = .
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