Galactic Exchange - posted November 6, 2000

Introduction

It's the year 2075. You take a vacation to the planet Orange. When you arrive, you notice coins of three different shapes: squares, circles, triangles. Unfortunately, no one speaks your language, and you're hungry. You find a food vending machine, but the prices are worn off! You have to try different combinations of coins to get food, and in addition, you will be able to figure out the relationships between the coins.

Applet



Click here to show vending machine

Questions:

  1. Buy a package of zoogs. What is the fewest number and types of coins needed to puchase a package of zoogs using exact change?

  2. Which coin is worth the least and how many does it take to equal each of the other coins?

  3. How many of the least valuable coins would it take to buy a package of zoogs?

  4. Buy a package of Glorps. What is the fewest number and types of coins needed to purchase a package of Glorps using exact change? How many of the least valuable coins would it take to buy a package of Glorps?

  5. Another Earthling arrives on the next shuttle and wants to try some Mushniks. Explain how you figured out the relationship between each coin.

  6. What is the fewest number and types of coins needed to purchase a package of Mushniks using exact change?