Question

Two friends Anil and Ashraf were born in the December month in the year 2010. Find the probability that:

1. They share the same date of birth.
2. They have different dates of birth.

Answer 1

Total possible outcomes for both birthdays = 31 × 31

= 961

Outcomes that are favorable for having the same birthday on December = 31

i. P(same birthday) = `31/961`

= `1/31`

ii. P(different birthday) = `1 - 1/31`

= `(31 - 1)/31`

= `30/31`