If a drop from 25 to 5 is a loss of 80%, what is the % gain from 5 to 25?
Set 11
Percent Calculation
Guess (or figure out) the unknown number. Fifty percent more than this number is 25% less than 60% more than 10.
Main Street Houses, Liars
Amy, Chris, Susan and Penny all live in different houses on Main Street. By a curious coincidence, the age of each woman is either seven years greater or seven years less than the number of her house. All of them are over 15 years old and less than 90; their ages are all different.
Amy said that the number of Chris’s house was even, and Chris remarked that the number of her house was greater that that of Penny’s. “My age,” she added proudly, “is a perfect cube.”
Susan said that the number of her house was greater by 3 than that of Amy’s, and that Penny’s age was an exact multiple of Amy’s age.
Penny, who has an unfortunate habit of complicating things, said that Chris’s age was either 27 or an even number other than 64. “Furthermore,” she commented, “Susan does not live at number 19.”
These remarks were unfortunately not all true. It was interesting to note that all remarks made by anyone who lived in an even-numbered house were false, and all remarks made by anyone who lived in an odd-numbered house were true.
What are their ages and the numbers of their houses?
Video Games, One Statement True
“Feldman owns more than 500 video games,” Anne says.
“Oh, no. Feldman owns fewer games than that,” Bruce says.
“One thing’s for sure,” Carson says. “Feldman owns at least one video game.”
If only one of these statements is true, how many video games does Feldman own?
Chemistry Puzzle
A chemist prepares four solutions late on a Friday afternoon, but forgets to label the container bottles before rushing home for the weekend. Monday morning she discovers her error and realizes that she does not know which bottle contains which colorless solution. She wonders how she can identify the solutions so that she does not have to prepare new ones.
The four bottles contain solutions of sodium chloride (NaCl), hydrochloric acid (HCl), calcium chloride (CaCl2), and sodium carbonate (Na2CO3). The chemist knows that if she mixes solutions of hydrochloric acid and sodium carbonate she will produce fizzing from the carbon dioxide (CO2) gas resulting and that mixing solutions of calcium chloride and sodium carbonate will produce a white solid precipitate, calcium carbonate (CaCO3), on the bottom of the mixing vessel. Mixing any other pair-combinations of solutions only produces another colorless solution.
She identifies each of the four unlabeled solutions. How does she do it?
Playing Cards Arrangement
Three cards from an ordinary deck are lying face down in a row. From the following information can you figure out what each card is?
- To the left of a Queen, there is a Jack.
- To the left of a Spade, there is a Diamond.
- To the right of a Heart, there is a Diamond.
- To the right of a King, there is a Spade.
Crypt-Prod: Digits Used Once 1
| 2 | ||||||
| x | 8 | |||||
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| 5 | ||||||
In this multiplication problem, each of the digits 1 through 9 has been used once and only once. Can you fill in the blanks so it works?
Quasi-Pascal Triangle
| 1 | 1 | 1 | ||||||
| 1 | 2 | 3 | 2 | 1 | ||||
| 1 | 3 | 6 | 7 | 6 | 3 | 1 | ||
| 1 | 4 | 10 | 16 | 19 | 16 | 10 | 4 | 1 |
Given the chart at the right, find the general rule and write the next three rows.
7 and 11 Become Even
You know, of course, that 7 and 11 are odd numbers. Without using addition, subtraction, multiplication, or division, show how you can make both of these numbers even.
