Question 1122816
There are two equations and two unknowns:

1.   P(H) = 12*P(T)
2.  P(H) + P(T) = 1<br>

12P(T) + P(T) = 1  
13 P(T) = 1<br>

P(T) = {{{ highlight(1/13) }}}   —>  P(H) =  {{{ highlight(12/13) }}}