A farmer has chickens and pigs in a field. Together, they have 15 heads and 40 feet. How many pigs are in the field?
5
Let C be chickens and P be pigs. C + P = 15, and 2C + 4P = 40. Multiply the first equation by 2: 2C + 2P = 30. Subtract this from the second equation: (2C + 4P) - (2C + 2P) = 40 - 30 => 2P = 10 => P = 5.
About this riddle
Math riddles hide a calculation inside a short story. Pull out the numbers, work out what is being asked, and watch for a trick such as a unit change.
Difficulty: Medium. More like this: Math riddles with answers or try Target 24 for a different kind of puzzle.
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