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Answered

What is the 10th term of the sequence 64, 16, 4,...?

A1/1024

B1/256

C1/4096

D1/496

Verified Answer :

Each time we are dividing by 4.
Essentially, multiplying by 1/4.
Since we're multiplying, that makes this a geometric sequence!

So: Our first term is 64, and the common ratio is 1/4.
Let's plug that into the geometric sequence formula.

\(a_n=a_1(r)^{n-1}\)

Where a_n = the value of the nth term
a_1 = the first term, and r = the common ratio

\(a_n=64(\frac14)^{n-1}\)

Now that we have our equation, let's plug in 10 for n.
That way, we can solve to find \(a_{10}\), the value of the 10th term.

\(a_{10}=64(\frac14)^{10-1}=\boxed{\frac{1}{4096}}\)

the answer is C. 1/4096