basically you just divide by 2 each time
0.2, 0.1, 0.05, 0.025, 0.0125, 0.00625, 0.003125
The 7th term is 0.003125.
Another way to solve this is making an equation
An=A1 x r^(n-1)
Where A1 is the first term
An= the nth term in the sequence
n= the term number that you want
r= the common ratio
A7=.2x(.5)^6=0.003125