Past Challenges

 

Up
bulletHow many of you have seen fields growing crops that look like the fields below?
bulletFarmers in drier parts of the country use circular irrigation methods to water fields.

bulletHow it works is that at the center of each of these circular fields is a huge water pipe that pumps
bulletwater along an arm (like below) that sprays water on top of the field.  A farmer then moves the
bulletarm in a circular pattern all the way around the field  so that the whole circle (field) gets watered.

bulletThe algebra challenge this week is this:
bulletWhat if the farmer decided to walk around the outside of his entire field. 
bulletThe irrigation "arm" that he has is a half mile long.  How far would that farmer walk?

 

Simplify:

Five boys went to the store to buy some treats.  One boy had $4.00.  One boy had $3.00.  Two boys had $2.00, and one boy had $1.00.  Using the following clues, determine how much money each boy started with and how much each had when he left the store ($1.65, $0.95, $0.70, $0.40, and $0.10).

  1. Alex started with more than Jim.

  2. Scott spent 15 cents more than Dan.

  3. Duane started with more money than just one other person.

  4. Alex spent the most, but he did not end up with the least.

  5. Dan started with 66% as much as Scott.

  6. Jim spent the least and ended up with more than Alex and Dan.

  7. Duane spent $0.35.

 

Move three of the circles below to make the arrow point in the other direction.

 

The arrangement of numbers above represents a pattern.  This pattern is a mathematical relationship among the numbers on the outside of each square with the number in the middle.  Can you discover the relationship?  If so, then what number belongs where the question mark is?

Hint:  The upper right number does something different (mathematically) that the other three outside numbers.

 The 8th grade Algebra Challenge this week is an easy one:

 

For the 7th graders, try this one:

Simplify:

Four men went fishing, their names were Sammy, Joe, Torkel, and Fred.  They caught six fish altogether.  One man caught three, another two, one caught one, and one didn't catch anything.  Which man caught how many fish?  What did each of the fisherman use for bait?

  1. The one who caught two fish wasn't Sammy nor the one who used worms.
  2. The one who used the flatfish didn't catch as many as Fred.
  3. Dry flies were the best lure of the day, catching three fish.
  4. Torkel used eggs.
  5. Sammy didn't use the flatfish.