Math, 28.10.2019 20:29
Joy lives in a street with house-numbers 8 up to 100. wally wants to know at which number joy lives. he asks her: "is your number larger than 50? “ joy answers, but lies. upon this, wally asks: "is your number a multiple of 4? “ joy answers, but lies again. then wally asks: "is your number a square? “ joy answers truthfully. upon this, wally says: "i know your number if you tell me whether the first digit is a 3.“ joy answers, but now we do not know whether she lies or speaks the truth. thereupon, wally says at which number he thinks joy lives, but (of course) he is wrong. what is joy’s real house-number?