HUES 6th Grade Math Choice #16 23-May-2000

Hollis Upper Elementary School, Hollis, New Hampshire

1.  Add up three adjacent dates on a calendar.

1A.  If the three dates sum to 51 and are in a row, what are the dates?
1B.  If the three dates sum to 42 are are in a column, what are the dates?

Source: Mathemagic, by Raymond Blum, 1991, pages 102-103

2. Chamique the Archer - posted 22-May-2000

Chamique (pronounced sha-mi-kwa), the best basketball player in the world, practices archery in her off-season.  One day she was really confused.  She wanted to know if she had a better chance of hitting the white or red parts of the target.

The target is made from concentric circles forming rings of alternating colors. The bull's-eye is red. The target has an overall diameter of 18 inches.  Starting from the outside edge, each circle decreases in radius by two inches.  You can assume that her shots all hit the target (much like her basketball shots), but are randomly distributed within the target area.

2A. What is the area of the target?
2B. What is the area of the bull's-eye?
2C. What are the probabilities of hitting each color?
2D. What is the probability of hitting a bull's-eye?

Source: The Math Forum

3. 1993-94 Annual 7th grade math contest

3.22.  Four monkeys are in a barrel.  The sum of their ages 5 years ago was 80.  What is the sum of their ages today?

3.24.  The average of 8 numbers is 10.  What is the average of these eight numbers and 1?

3.31.  If 1 horse weighs as much as 15 dogs, and 3 dogs weigh as much as 8 cats, then 5 horses weigh as much as how many cats?

3.34.  7/3 is how much more than 3/7?

3.38.  1 + 2 + ... + 49 + 50 = 1275, then 51 + 52 + ... + 99 + 100 = what?

Source: The Math League

Don Braffitt