Did You Find Out? Get the Answer to the Riddle of E-News Issue No. 3, August 2022
X Sentences Are False
Which sentence is correct?
Two men have fun and write 100 sentences on a sheet of paper and number them from 1 to 100. The first sentence is: “Exactly one sentence on this sheet is false,” the second: “Exactly two sentences on this sheet are false,” and so on.
But which sentence is correct now?
Solution
The sentences on the sheet all contradict each other. Each sentence gives a different number of sentences that are false. However, one of the sentences must be true, because sentence number 100 rules out the possibility that all the sentences are false—it would be true that 100 sentences are false, but the sentence says they are all false. So it doesn’t tell the truth. So if one sentence is true, it is sentence number 99, because 99 sentences are false.
Pepperl+Fuchs (India) Pvt. Ltd.
Ground Floor, #546/1, Sy. No. 46, 7th Main
4th Phase, Peenya Industrial Estate
Bangalore - 560058
India
info@in.pepperl-fuchs.com
+91 80 4609 6000
Pepperl+Fuchs is a leading developer and manufacturer of electronic sensors and components for the global automation market. Continuous innovation, enduring quality, and steady growth have been the foundation of our success for more than 70 years. Pepperl+Fuchs employs 6,300 people worldwide and has manufacturing facilities in Germany, USA, Singapore, Hungary, Indonesia and Vietnam, most of them ISO 9001 certified.