Sunday, September 19, 2010
Monday, July 19, 2010
Tuesday, July 6, 2010
You have 5 bags of gems each containing 10 gems. All gems have the same shape and size. Each gem weighs 10 grams so a bag weighs 100 grams. But there is a bag of gem that contains gems with 9 grams (bag weighs 90 grams). You have a weighing scale that can register a maximum of 200 grams. What is the least number of times you could use the scale to find the bag with 9g gems?
Twos to Five
Thursday, June 24, 2010
3 men were held captive by an Indian tribe and they are positioned as the illustration above. The chieftain showed them 5 headbands, 2 red and 3 white. The 3 men were blindfolded and the chief put a headband on each of their heads, hid two remaining headbands, and removed their blindfolds.According to the rules any one of the three men could speak first and try to guess his headband color. And if he guessed correctly they passed the test and could go free, if not they failed. It so happened that all 3 men were prominent logicians from a nearby academy. So after a few moments of silence, the first man in the line said: "My headband is ...".
What color was his head band? Why?