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Dining Ducks

Age 7 to 11
Challenge Level Yellow starYellow starYellow star
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Dining Ducks


Every healthy duck is greedy and every old duck is greedy.
On a particular farm, some ducks are greedy and some ducks are not.

Which of the following statements about the ducks on that farm must be true?

  1. There are both young ducks and old ducks.
  2. All the ducks that are not greedy are young.
  3. Some of the young ducks are sick.
  4. All the sick ducks are young.

pic 1


This problem has been adapted from the book "Sums for Smart Kids" by Laurie Buxton, published by BEAM Education. This book is out of print but can still be found on Amazon.


Why do this problem?

This problem can be used as a good introduction to discussion that involves some logical thinking.

Possible approach

Good to set this up with everyone in a circle ready for a session based upon talking and listening and reasoning.

Key questions

Why do you think that?
Could you help others understand what you think?
Do you agree with . . . . ?

Possible extension



Possible support


 

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The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to embed rich mathematical tasks into everyday classroom practice.

NRICH is part of the family of activities in the Millennium Mathematics Project.

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