Math CentralQuandaries & Queries


Subject: odd numbers
Name: emma
Who are you: Student

can 4 odd numbers equal 21?

i was given this pig pen problem. if there are 21 pigs and only 4 pig pens how can you distribute the pigs into the pens and have an odd number of pigs in each pen.
it doesn't seem possible to me. i need help!

Hi Emma,

You're right, you can't add four odd numbers to get 21. There is a trick to this problem. Normally four pig pens would be in four separate locations. Can you think of an alternative way of placing the pens that would solve the problem?


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