3.2 Exercise 3

In a certain population, the probability a woman lives to at least seventy years is 0.70 and is 0.55 that she will live to at least eighty years. If a woman is seventy years old, what is the conditional probability she will survive to eighty years? Note that if $A \subset B$ then $P \left(A B\right) = P \left(A\right)$.