ModeratorOne
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I will post the answers to these later so no one can cheat :-)
I love these!
1. A scientist is experimenting with bacteria that are one micron in diameter and that reproduce by dividing every minute into two bacteria. At 12:00 PM, he puts a single organism in a container. At precisely 1:00 PM, the container is full.
At what time was the container half full?
How big was the container?
2. Three students checked into a hotel and paid the clerk $30 for a room ($10 each). When the hotel manager returned, he noticed that the clerk had incorrectly charged $30 instead of $25 for the room. The manager told the clerk to return $5 to the students. The clerk, knowing that the students would not be able to divide $5 evenly, decided to keep $2 and to give them only $3.
The students were very happy because they paid only $27 for the room ($9 each). However, if they paid $27 and the clerk kept $2, that adds up to $29. What happened to the other Dollar?
3.
When we rearrange the pieces of the upper picture to form the lower picture we have a missing square. The pieces in both pictures are identical. Can you explain why the square is missing?
4. A bartender gets an ice cube weighing 20 grams from an ice bucket and puts it into an insulated cup containing 100 grams of water at 20 degrees Celsius. Will all the ice melt? What will be the final temperature of the water?
5. My sister has six red stamps and three blue ones. In her collection, seven stamps are from Mexico and six stamps are from France. One stamp is purple and it is not from Mexico or France. Two of her Mexican stamps are red and one is blue. Two of her French stamps are blue and three are red. How many stamps does she have?
6. At a party, everyone shook hands with everybody else. There were 66 handshakes. How many people were at the party?
7. The government pays farmers a specific fee for each row of four trees that they plant. An enterprising, but dishonest farmer found a way of planting five rows of four trees using only ten trees. How did he do it?
8. Mathematical aptitude tests frequently have sets of numbers where you are supposed to figure out a pattern or guess the next number. For example,
(2, 4, 6, 8, 10) is a list of even numbers corresponding to 2×n for n=1, 2, 3, ...
(1, 1, 2, 3, 5) is the well-known Fibonacci series where two adjacent numbers are added to produce the next number.
(1, 2, 3, 5, 7) is a list of prime numbers.
(1, 2, 4, 8, 16) is an exponential series corresponding to 2n for n=0, 1, 2, ...
Can you figure out the special significance of the following sequence? (2, 6, 10, 15, 19)
9. All students in the physics class also study mathematics. Half of those who study literature also study mathematics. Half of the students in the mathematics class study physics. Thirty students study literature and twenty study physics. Nobody who studies literature studies physics. How many students in the mathematics class study neither physics nor literature?
10. Hydrochloric acid is a corrosive, fuming, poisonous, highly acidic solution of hydrogen chloride (HCl). Sodium hydroxide is a caustic, strongly alkaline compound (NaOH) used in drain cleaners. If ingested, hydrochloric acid corrodes the mucous membranes, esophagus, and stomach causing dysphagia, nausea, circulatory failure and death. Sodium hydroxide, if ingested, will cause vomiting, prostration, and collapse. Why is it that if you mix these two substances in the right proportions before ingesting them you will not have any poisoning symptoms?
11. There are twelve identical-looking balls, but one is either heavier or lighter than the other eleven. How can you determine which is the odd ball and find out whether this ball is heavier or lighter than the others using only three weighings with a balance?
12. It is said that Galileo (1564-1642) dropped balls of various weights from the top of the Leaning Tower of Pisa to refute an Aristotelian belief that heavier objects fall faster than lighter objects. If the balls were dropped from a height of 54 meters, how long did it take for the balls to hit the ground? and How fast were the balls going when they hit the ground?
13. A toy ship is floating in a cylindrical container 10 centimeters in diameter that is partially filled with water. How much will the level of the water rise if a silver teddy bear weighing 100 grams is loaded on the ship? By the way, silver has a density of 10.49 g/cc.
If the teddy bear falls off the ship and sinks to the bottom of the container while the ship continues to float, how much will the level of the water rise compared to the original level with just the ship?
14. The grandson is about as many days old as the son is in weeks. The grandson is approximately as many months old as the father is in years. The ages of the grandson, the son, and the father add up to 120 years. What are their ages?
15. You have to measure exactly 4 liters of water, but you only have a 3-liter bottle and a 5-liter bottle. How do you do it?
< Message edited by ModeratorOne -- 8/6/2005 4:44:21 PM >
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