Multiple choice general knowledge

A person has certain number of cows and birds. They have 172 eyes and 344 legs. How many cows and birds does he have?

  1. 0 cow, 86 birds

  2. 86 birds, 5 cows

  3. 0birds , 86 cows

  4. 5birds , 86 cows
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let cows = c and birds = b. Each has 2 eyes: 2(c + b) = 172, so c + b = 86. Cows have 4 legs, birds have 2 legs: 4c + 2b = 344. Substituting b = 86 - c: 4c + 2(86 - c) = 344, which gives 2c = 172, so c = 86 and b = 0. Thus there are 86 cows and 0 birds.

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