#### The probability that a non leap year selected at random will contain 53 Sundays is (A) $\frac{1}{7}$                    (B) $\frac{2}{7}$                     (C) $\frac{3}{7}$                     (D) $\frac{5}{7}$

Solution. Probability: probability means possibility. It is a branch of mathematics that deals with the occurrence of a random event. The value is expressed from zero to one.
In 365 days there are 52 weeks and 1 day.
If it contain 53 sunday then the 1 day of the year must be sunday.
But there are total 7 days.
Hence total number of favorable cases = 1
Hence probability of 53 sunday = $\frac{Number\, of\, favourable\, cases}{Total\, cases}$

$= \frac{1}{7}$