What is the nth term of the geometric sequence 2,10,50,250?

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Answer 1 · 2016-02-15T02:08:59

Use the explicit formula for a geometric sequence:

#a_n=a_1(r)^(n-1)#

First, find the common ratio #r=10/2=5#

Now, insert the values from the problem into the explicit formula ...

#a_n=2(5)^(n-1)#

So, for example if you want to know the 11th term ...

#a_11=2(5)^((11-1))=19,531,250# [wow! that's a big number!]

Hope that helped!