Brainbusters


 * SPLAT! **

Two trains 200 miles apart are moving toward each other; each one is going at a speed of 50 miles per hour.  A fly starting on the front of one of them flies back and forth between them at a rate of 75 miles per hour. It does this until the trains collide and crush the fly to death. (ALL train passengers were safely rescued, by the engineers and conductors.)

What is the total distance the fly has flown?


 * What's wrong with this algebra ? I mean, aside from the result, of course!! **

** by factoring out the constants: ** ||= ** 4(a + b - c) = 3(a + b - c) ** ||
 * = ** Start with a simple addition equation: ** ||= ** a + b = c ** ||
 * = ** Rename each term by using addition: ** ||= ** 4a - 3a + 4b - 3b = 4c - 3c ** ||
 * = ** Reorganize by adding and subtracting: ** ||= ** 4a + 4b - 4c = 3a + 3b - 3c ** ||
 * = ** Reverse the distributive property **
 * = ** Divide both sides by (a+b-c) ** ||= ** 4(a + b - c) / (a + b - c) = 3(a + b - c) / (a + b - c) ** ||
 * = =And our quotient tells us that ... = ||= =4=3 ...HOW CAN THIS BE? = ||

= = = You won the lottery! = ** You have a choice: **

** You can have one dollar today **

** OR... **

** an infinite amount of money paid out ** ** over an infinite length of time. **

** Why might the dollar be a better choice? **