Answer
$\frac{1}{128}$
Work Step by Step
P(E) = P(A)*P(B)
Assume that we are flipping a coin in a fair manner. Find the probability of some series of events, E, happening. Let A be the first event, B be the second event, and so on.
We consider the chances of getting tails 7 times in a row:
P(A) =P(B)=P(C)=P(D)=P(E)=P(F)=P(G)= $\frac{1}{2}$
P(E) = P(A)*P(B)*P(C)*P(D)*P(E)*P(F)*P(G)
P(E) = $\frac{1}{2^{7}}$
= $\frac{1}{128}$