September 28 Challenge



Click here for a link to this week's Math Enrichment Problem of the Week
DUE Friday, September 28
 




 

September 21 Challenge

Samantha is experimenting with three spinners.  Each spinner is divided into three equal sections with a number in each section. 

Spinner A shows 8, 6, 1;
Spnner B shows 7, 5, 3;
Spnner C shows 9, 4, 2.

Samantha spins two spinners and recored as winner the one that stopped on the greater number.  She has already found that A usually wins over B and the B usually wins over C.  She guesses that A will usually win over C. 

Is her guess correct?

Find the probabilities that A wins over B and that B wins over C. 

If spinners A and C are spun, which one do you think will win most often?

Answer:

Her guess is wrong.

P(A wins over B) = .56

P(B wins over C) = .56

P(A wins over C) = .44  So, C will win over A 56% of the time.

September 14 Challenge

How many domino pieces (bones) are in a double-fifteen set?

Remember there will be a double-zero, a double-one, and so on to double-fifteen, and that one-zero is the same as zero-one.

Answer: 136

For more information, go to:
http://en.wikipedia.org/wiki/Dominoes

Due December 4

Answer to Last Week's Problem:
3:00 A.M., 3:00 P.M., 9:00 A.M., 9:00 P.M.


Today's Problem:

In a far-off land, three fish can be traded for two loaves of bread, and a loaf of bread can be traded for four bags of rice. How many bags of rice is one fish worth?

Due November 27

Answer to Yesterday's Problem:
25 triangles. The perimeter will be a + a + b = 99, where a represents the lengths of the equal sides and b represents the base, or the third side. It follows that a + a must be even, since the sum of two odd numbers or the sum of two even numbers will always be even. Therefore, the base b must be an odd number in length to allow an even number plus b to equal 99. Therefore, to test the numbers, the possible lengths of the base must include 1 to 97, inclusive. However, the sum of the two equal lengths must be greater than the length of the base for the three segments to form a triangle. When the base length reaches 51, this situation is no longer possible (24 + 24 = 48). Therefore, the greatest length of a base will be 49 inches. The base includes the odd numbers 1 to 49, inclusive, which will provide 25 triangles. The possibilities are listed below.

25, 25, 49
26, 26, 47
27, 27, 45
28, 28, 43
29, 29, 41
...
49, 49, 1


Today's Problem (5 points):
Find all the times, on the hour, when the minute and hour hands of a clock form a 90 degree angle.