Ted was lost while driving around the country and saw a house. He parked under a nearby tree and started toward the house. As soon as he got out of his car a huge dog lunged at him from the opposite side of the tree. Fortunately the dog was chained and Ted managed to stay out of reach. Finding no one home at the house, Ted returned to his car, but as he approached the dog lunged at him again. The chain was so long the snarling animal could reach both car doors. How did Ted escape the dog and get back into his car?
Ted moved slowly around the tree keeping just out of the dog’s reach. The animal followed, winding its chain around the tree until it was too short to reach Ted’s car
You have two coins of equal size on a table, situated end to end vertically. If you roll the top coin around the bottom coin until it returns to its original position, how many times will it have rotated?
You are given eight coins and told that one of them is counterfeit. The counterfeit one is slightly heavier than the other seven. Otherwise, the coins look identical. Using a simple balance scale, how can you determine which coin is counterfeit using the scale only twice?
First weigh three coins against three others. If the weights are equal, weigh the remaining two against each other. The heavier one is the counterfeit. If one of the groups of three is heavier, weigh two of those coins against each other. If one is heavier, it’s the counterfeit. If they’re equal weight, the third coin is the counterfeit.