Question

The probability that the ${13}^{th}$ day of a randomly chosen month is a Friday, is

• A. $\frac{1}{12}$
• B. $\frac{2}{3}$
• C. $\frac{1}{84}$
• D. $None$

Answer 1

The correct option is C $\frac{1}{84}$

Probability of selecting a month =$\frac{1}{12}$
${13}^{th}$ day of a randomly selected month is Friday if its first day is Sunday.
Probability of this event =$\frac{1}{7}$
Hence required probability $\frac{1}{12}\times \frac{1}{7}=\frac{1}{84}$.