Puzzles

Try your mental skills on the following puzzles. The first person submitting all correct answers to the Technical Review will win a prize. Answers will be published on the website after a winner is declared.

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