Let $\displaystyle Q_n$ denote the probability that in $\displaystyle n$ toss no heads comes up 3 times in a row. How do we show the probability of this happening?
Anyone ?
$\displaystyle Q_0 = Q_1 = Q_2 = 0$
$\displaystyle Q_3 = 7/8 $ because the only possible outcome of 3 heads is $\displaystyle \{ H H H \} $Then i dont know how to do for Q_4
logically i thought it would be $\displaystyle 14/16 = 7/8 $ But what am i missing? i thought the only possibilities would be $\displaystyle \{ THHH, HHHT \}$