213. There are 7 tennis balls which are identical in all aspects except that one of them weighs slightly less than the other 6. How can you identify the one that weighs less on a balance scale with no more than 2 separate weighings?
215. Can you arrange the odd digits 1, 3, 5, 7, and 9, and the even digits, 2, 4, 6, and 8, in such a way that the odd ones add up to the same as the even ones? You can use arithmetical signs and decimals, but the idea is to try and arrive at the simplest possible solution. There are, of course, many possible answers.
217. Many years ago when gasoline was only 46 cents a gallon, I stopped to fill up my car. I gave the attendant a $20.00 bill and waited for my change. Unexpectedly, he charged me for the number of gallons that the car needed instead of the dollar amount. (for example if the car took 8.4 gallons he would have charged me $8.40. Because he did this, I received less in change than I should have. The funny thing is that I had received in change exactly the amount that I should have been charged for the gas in the first place. Remembering that the cash indicator on a gas pump will only charge to the nearest half-cent, how many gallons of gas did I buy that day?
220. What is the four-digit number (no zeros) in which the third digit is the number of "winds," the first digit is one-half of the third, the second digit is double the third and the last digit is one-half the sum of the first three?
221. From doing the wacky words puzzles on our website, you know that the letters CCCCCCC can be interpreted as The Seven Seas. Can you make sense out of
224. The square of 13 is 169. Take the last digit of the square, 9, and place it in the middle, making 196. This is the square of 14, the next number above 13. What are the next numbers which also have this property?
225. Find the word that fits the first definition, then add a "T" in front of it to make a new word that matches the second definition.
Place a "T" in front of the place you are, and make the other place.
Place a "T" in front of a male possessive, and get something you can point to.