Given a venn diagram in picture representing two sets. The blue set B represents the number of people who eat break fast almost every day. the orange set C represents the number of people who buy cereal atleast once a month.
n(B) = 11+53 =64
n(c) = 53+4 = 57
n(BC) = 53
Required probability = (Prob that the person buys cereal atleast once a month/he eats breakfast almost every day)
= P(C/B) = P(BC)/P(B) = n(BC)/n(B) = 53/64
Hence answer is 53/64
Option 3 is the right answer.