NDA 2016 Maths · Mathematics · Probability · hard

The probability that a leap year selected at random has 53 Sundays is

Single correct option

The probability that a leap year selected at random has

53

Sundays is

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Answer: (B) $\dfrac27$

A leap year has

52

weeks and

2

extra days. The pair of extra days is one of

7

equally likely pairs, and

2

of them include Sunday (Sat-Sun, Sun-Mon). So the probability is

2/7

;

1/7

is for a non-leap year.

Original question written in the NDA 2016 Maths pattern and checked twice for the correct answer. Not an official question paper. How we write and check questions · Corrections policy · Report a mistake