MathDB
Cats and sacks for sale

Source:

April 19, 2013

Problem Statement

There are 2020 cats priced from $12\$12 to $15\$15 and 2020 sacks priced from 1010 cents to $1\$1 for sale, all of different prices. Prove that John and Peter can each buy a cat in a sack paying the same amount of money.