Answers to Mathematics Trivia

Here are the answers. I put the explanations for problems that most or all people got wrong. I do have the explanations for everything though. So if anyone has any questions and would like to see how a problem was solved, let me know and I will post them.

1. What is the figure that is defined to be the set of all points in the plane that are equidistant from a single point?
b. A circle

2. What is the only type of triangle the Pythagorean Theorem can be used on without being given any other measurements besides the sides (no height given)?

Right

3. Which of the following fractions is the largest:
b. 31/60

4. If 16 ½ feet equal 1 rod, how many inches are in 4 rods?
d. 792
5. On a map, 1 centimeter represents 35 kilometers. Two cities 245 kilometers apart would be separated on the map by how many centimeters?
b. 7

6. If GEOMETRY means 'earth measurement', what does TRIGONOMETRY mean?

a. Triangle Measurement

7. To change 3 miles to inches, you should
c. multiply 3 times 5,280 and then multiply by 12

8. Helen purchased three times as many carnations as roses. If roses cost $1 each, and carnations cost $.50 each, and she spent a total of $7.50 for the flowers, how many roses did she purchase?
b. 3

9. What is the next number in this sequence? 0, 2, 6, 14, 30, ... ?

62

10. What will be the diameter of a circle with circumference 12 inches?

b. 3.82 inches

11. Between 9 a.m. and noon, how many degrees does the hour hand of a clock move?
c. 90

12. A college graduate goes to work for $x per week. After several months, the company gives all the employees a 10% pay cut. A few months later, the company gives all the employees a 10% raise. What is the college graduate’s new salary?
b. .99 $x

13. An automobile traveled 6 hours at an average speed of 40 miles per hour. It averaged only 30 miles per hour on the return trip. What was the approximate average speed in miles per hour for the round trip?
b. 34

14. The cost of 30 onions is d dollars. At this rate, how many onions can you buy for 80 cents?
a. 24/d

15. Two cars leave the same location at 2 p.m. If one car travels north at the rate of 30 mph and the other travels east at the rate of 40 mph, how man miles apart are the two cars at 4 p.m.?
b. 100 miles
The cars start at the same point and the first travels 60 miles north and the other 80 miles east. The distance between them is now the hypotenuse of a triangle. So you use the Pythagorean theorem to figure out the distance.

16. What is the cost in dollars to carpet a room x yards long and y yards wide if the carpet costs two dollars per square foot?
e. $18xy
Abbie was the only one who got this right! The room is measured in yards, but the cost is in feet. There are 9 square feet in a yard and the cost was $2 per square foot, so the cost is $18 per square yard. To figure out the cost to carpet the room, it is the cost times the area, which is $18xy.

17. John is three times his son’s age. If the difference between their ages is 30 how old is the son?
c. 15

18. How many ice cubes, measuring 2 inches on an edge, can be held in a container measuring 8 inches deep, 5 inches high, and 4 inches wide?
a. 16

19. Mrs. Jones wishes to buy 72 ounces of canned beans for the least possible cost. Which of the following should she buy?
a. six 12-ounce cans at $.39 per can

20. If the profit gained on the sale of an article is 10% of the selling price, and the original cost of the article is $12.60, the article must be marked for sale at
e. $14.00
Maria was the only one who got this right!
If $12.60 is the cost of the article and the profit is to be 10% of the selling price, than $12.60 is 90% of the selling price.
.9x=$12.60
x= $14.00


The results:
Maria got 8 out of 20. Maria, Marty and I thought those damn Praxis people were wrong with #20 until we rethought the problem. You were the only one who got it right. And it was a question about shopping. Good job.

Mom got 10 out of 20 correct. It has been a long time since she took a math class, so I thought this was pretty good.

Abbie and Joe both got 14/20 correct. Abbie said "This is probably why I am a social worker." Abbie, you tied with the engineer!! Joe, you tied with the social worker!

Our winner is....


KAREN!!! Karen got 16 out of 20 and she is a nerd. Just kidding. Way to go, Karen. Maybe you should try to play more often.

Good job everyone. Thanks for playing!