A man has some hens and cows. If the number of heads be 50 and the number of feet equals 160, then the number of hens will be:
Choose the correct choice from the following:  A) 22  B) 23  C) 24  D) 20  E) 28
Explanation:   Let the number of hens be x and the number of cows be y.   Then, x + y = 50 .... (i)   and 2x + 4y = 160 x + 2y = 80 .... (ii)   Solving (i) and (ii) we get: x = 20, y = 30   The required answer = 20.   Answer: 20
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A man has some hens and cows. If the number of heads be 50 and the number of feet equals 160, then the number of hens will be: