reply on: [Daily puzzle] Light bulb problem \ stacker news ~science

149 sats \ 6 replies \ @bordalix 3 Nov \ on: [Daily puzzle] Light bulb problem science

I have one for you:

A friend of mine has 2 daughters (not twins) under 10 years old and wants you to guess the sum of their ages, but the only clue he gives is that the last digit of the product of their ages is the number of their house's door.

0 sats \ 5 replies \ @Scroogey 3 Nov

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22 sats \ 4 replies \ @south_korea_ln OP 3 Nov

Is that because 1 as last number is the only one that gives a unique solution to multiplying two non equal values below 10? E.g. 11, 31, 41,... can't be obtained in such a way?

0 sats \ 3 replies \ @Scroogey 3 Nov

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22 sats \ 0 replies \ @south_korea_ln OP 3 Nov

I like this problem. The answer only hit me after i read your suggestion though. I assumed trolling at first...

0 sats \ 1 reply \ @Scroogey 3 Nov

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1 sat \ 0 replies \ @bordalix 3 Nov

Correct. Remember, he didn't ask for her ages, he asked for the sum of it. In both possible solutions, the sum is the same, 10 ;)