How do you find the 10th term in the geometric sequence 320, 160, 80, 40, ...?

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Answer 1 · 2015-11-09T05:03:23

Geometric progression

320 , 160 , 80 , 40 , .....

First of all, you've to find the first term of the sequence,a,

first term, a =320

Then, you've to find the common ratio of the sequence.So,divide the second term with the first term,

common ratio, r = 160/320

                     r = 1/2

Use the formula #T_n = a(r^(n-1))#

#T_10 = 320[(1/2)^(9)]#

#T_10 = 5/8#