Question

The probability that two friends share the same birth-month is:

• A. $\frac{1}{6}$
• B. $\frac{1}{12}$
• C. $\frac{1}{144}$
• D. $\frac{1}{24}$

Answer 1

The correct option is B $\frac{1}{12}$

Two friends can share the same birth-month in 12 ways i.e. {January, February.......Dec}
So, favourable ways = 12
and total ways of falling birthdays = 12 × 12

So, required probability $=\frac{12}{12\times 12}=\frac{1}{12}$