*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, 12, 19 June: 14, 12 July: 16, 18 August: 14, 15, 16 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. Based on their statement guess the right birthday. Go ahead
Answers
Answer:
I don't understand your dates properly
Answer:
12 June
Step-by-step explanation:
Jack --> Knows Month
Andy --> Knows Number (date)
Hint 1: Jack doesn't know but is SURE Andy also doesn't know
If Jack knows the month and is 100% sure that Andy will not know the answer that means the month he knows does not have any unique values for date field (as knowing the date--> Andy could figure out the month automatically because of uniqueness) that crosses out May (unique date 19) and July (unique date 18)
Possible answers left:
June: 14, 12
August: 14, 15, 16
Hint 2: Andy was first confused but with Jack's answer (Hint 1) he now knows
Andy is left with above possibilities and knowing the dates he knows the answer, but we don't yet! The only outcome of this hint is: It can't be 14 otherwise Andy cannot figure out whether it's 14 June or 14 August.
Possible answers left:
June: 12
August: 15, 16
Hint 3: Jack after Hint 2 knows the answer
Let's take August (Jack knows the month), with Hint 2 Jack would have still been confused as there are 2 possibilities left. As Jack is certain now that means it has to be 12June (Month with just 1 possibility left)
TADA!!!
Possible answers left: