Question

*Lockdown Quiz*

Jack and Andy befriended a girl. They ask her what is her birthday. She does not give a straight forward answer, but gives some hints.

She gives them the following 10 dates to pick her birthday.

May: 15, 16, 19
June: 17, 18
July: 14, 16
August: 14, 15, 17

Then she discloses correct month to Jack and the correct date to Andy.

She asks Jack to guess the right birthday. He says sorry I can't, but I am sure even Andy won't be able to guess it right.

Now Andy says, I was a bit confused but with Jack's statement, I know what is her birthday.

Now Jack says if that is the case, I also know what is it.

Both guessed it right. Use simple logic to guess the right birthday. Go ahead

Answer 1

Answer: 16 July

Explanation:

1. If date was 18 or 19, then Andy would have been sure about the exact DOB. Jack is sure that Andy doesn't know....this implies... Jack knows that date can't be 18 or 19....which is possible for him to know only when month is either July or August.

2. Jack knows the month but Andy doesn't and after hearing Jack's statement, Andy was able to make out that month is either July or August (as we were able to make that out)

3. Andy was earlier confused but now he is not....which implies date is not 14....as it is there in both July and August. So now probable dates are 15, 16, or 17. All these dates appear twice in given 10 options....but after ruling out May and June it becomes very easy for a person who knows the date and not month.

4. Now that Jack knows that Andy is no more confused....he is sure that date is not 14th...and as Andy already knows the month (which is July) he is sure about it being 16th July (only remaining option)

Answer 2

The answer is July 16th

1. If date was 18 or 19, then Andy would have been sure about the exact DOB. Jack is sure that Andy doesn't know
2. This implies Jack knows that date can't be 18 or 19 which is possible for him to know only when month is either July or August.
3. Jack knows the month but Andy doesn't and after hearing Jack's statement, Andy was able to make out that month is either July or August (as we were able to make that out)
4. Andy was earlier confused but now he is not which implies date is not 14
5. alAs it is there in both July and August. So now probable dates are 15, 16, or 17.
6. All these dates appear twice in given 10 options but after ruling out May and June it becomes very easy for a person who knows the date and not month.
7. Now that Jack knows that Andy is no more confused
8. Now that Jack knows that Andy is no more confused He is sure that date is not 14th...and as Andy already knows the month (which is July) he is sure about it being 16th July (only remaining option)