2.2.5 problem 38
Let S be the event that
an email is spam. Let L=Wc1,...,Wc22,W23,Wc24,...,Wc64,W64,W65,Wc66,...,Wc100
Let q=∏j(1−pj)
where 1≤j≤100:j∉23,64,65.
Let x=∏j(1−rj)
where 1≤j≤100:j∉23,64,65.
P(S∣∣∣L)=P(S)P(L|S)P(L)=pp23p64p65qpp23p64p65q+(1−p)r23r64r65x.