P(F OR N)=P(F)+P(N)-P(F AND N); P(¬F)=1-P(F)=0.36; P(¬N)=1-P(N)=0.67.
P(F OR N)=0.84=0.64+0.33-P(F AND N), P(F AND N)=0.97-0.84=0.13.
P(¬F OR ¬N)=P(¬F)+P(¬N)-P(¬F AND ¬N), P(¬F AND ¬N)=P(¬F)+P(¬N)-P(¬F OR ¬N).
P(¬F OR ¬N)=P(¬(F OR N))=1-0.84=0.16.
P(¬F AND ¬N)=0.36+0.67-0.16=0.87.