NDA 2012
- Exam
- NDA
- Year
- 2012
- Subject
- Mathematics
- Chapter
- Probability
NDA 2012 · Mathematics · Probability
What is the probability that a leap year selected at random will...
What is the probability that a leap year selected at random will contain 53 Mondays?
Options
- A
- B
- C
- D
Correct answer
A.
Step-by-step solution
A leap year contain 366 days i.e., 52 weeks and 2 days, clearly there are 52 Mondays in 52 weeks.
For the remaining two days, we may have any of the following two days.
(i) Monday and Tuesday
(ii) Tuesday and Wednesday
iii) Wednesday and Thursday
iv) Thursday and Friday
(v) Friday and Saturday
vi) Saturday and Sunday
sii) Sunday and Monday
Now for 53 Mondays, one of the two days must be Monday.
Hence, the required probability .