K12 Math Puzzles
Rosebush Puzzle 3*
A gardener laying out a third bed of roses planted 19 rosebushes in 9 straight
lines with 5 bushes in each line.
How did she do it?
or 9 toothpicks and 19 Cheerios or other flat breakfast cereal
9 sticks of uncooked spaghetti and 19 pennies
or whatever other manipulative is handy to simulate the lines and rosebushes
- Place 19 "rosebushes" on your desk or table.
- Using the 9 sticks experiment with arranging the "bushes" into 9 lines
of 5 each.
Questions to ask yourself as you work:
- If there are 5 bushes on each of the 9 lines and the lines are parallel, how
many bushes would there be in all?
- Since that would be 45 bushes and you only have 19 bushes to place, can the lines
- When you place 5 rosebushes on one of the lines, how many bushes do you have
- How many rosebushes are toward the inside, and how many are toward the outside?
(Don't look 'til you're ready to give up!)
* Thanks to Kate Ryan, who sent this question to Ask
Dr. Math at the Math Forum.
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