Puzzle Answers

Congratulations to Stacey Markus for correctly submitting the answers to the puzzles

1. Suppose you have two threads. Each of them will burn for one hour if one of its sides is set on fire. How can you measure 45 minutes exactly using only these threads and a lighter?

   
   

   Light both sides of one thread and one side of the other. After 30 minutes, when the first thread is consumed, light the second side of the other thread. This thread will burn for an additional 15 minutes - a total of 45 minutes.

   
   
   

2. A casino uses only $5 and $8 chips on its standard roulette wheel. What is the largest wager that cannot be placed?

   
   

   $27

   
   
   

3. Two trains, one traveling eastbound at 30 mi/hr and the second traveling westbound at 40 mi/hr, are 210 miles apart. A bird, which flies at 50 mi/hr, begins at one train and flies towards the other. When it reaches the second train, it turns around and heads back to the first. It continues in this fashion until the trains meet. How far does the bird travel before the trains meet?

   
   

   This problem can be solved using two methods. The first, and by far more complicated, is to sum the infinite series of distances traveled by the bird in between the trains. The second is to realize that the trains meet in 3 hours. Because the bird flies at 50 mi/hr, it will travel 150 miles in this time period.

   
   
   

4. A clock falls from the wall onto the floor and breaks into three pieces. The digits on each piece add up to the same total. What digits are on each piece?

   
   

   Piece 1: 11 + 12 + 1 + 2 = 26
   Piece 2: 9 + 10 + 3 + 4 = 26
   Piece 3: 5 + 6 + 7 + 8 = 26