Question

Assume that there is an equal chance of being born on an odd or even numbered day. A family has two children. If one child was born on an odd date, the probability that other child was also born on an odd date is?

Answer 1

There is an equal chance of being born on an odd or even numbered day so

P(born on odd numbered day) = P(born on even numbered day) = 1/2 = 0.50

Birth of one child does not effect the birth of other child. That is events ne child was born on an odd date and second child was born on an odd date are independent events. Therefore the probability that other child was also born on an odd date given that one child was born on an odd date is

P(2nd on odd numbered day | 1st on odd numbered day) = P(born on odd numbered day) = 0.50

Answer: 0.50