Help please

[7!/(5!*2!*2^7)] + [7!/(6!*1!*2^7)] + [7!/(0!*2^7)] =29 / 2^7 = 22.65625%

A fair coin is flipped 7 times. What is the probability that at least 5 consecutive flips come up heads?

All heads   + 6 heads with 5 in a row + 5 heads in a row

All heads, just 1 way

6 heads

THHHHHH

HTHHHHH

HHHHHHT

HHHHHTH

4 ways

5 heads

TTHHHHH

HHHHHTT

THHHHHT

3 ways

Total number of possible tosses = 2^7

So what answer do you think I might finish with?

Please let HelpBot be the next to answer. 

I get 8/2^7 !!!

Thanks!!!!