Question 853272
Find the type of sequence.  This is a geometric sequence with a common term of 1/4, because each term * 1/4 is the next term.<P>
For any geometric sequence, the nth term = {{{a(1) * r^(n-1)}}} where a(1) is the first term, n is the term number you're trying to find, and r is the common ratio.<P>
Let's test it with the third term.  The third term = {{{64*(1/4)^2}}} = 64/16 = 4.  That is the third term.  See, it works!<P>
The tenth term is {{{64*(1/4)^9}}} = 64/262144 = 1/4096.  The answer is c.<P>
If you didn't remember the formula, write out the terms, dividing each subsequent term by 4 (which is multiplying it by 1/4), until you reach the 10th term.<P>
64, 64/4=16, 16/4=4, 4/4=1, 1/4=1/4, 1/4 / 4 = 1/16, 1/16 / 4 = 1/64, 1/64 / 4 = 1/256, 1/256/4 = 1/1024, 1/1024 / 4 = 1/4096.