A man has some hens and cows. If the number of heads be 100 and the number of feet equals 180, then the number of hens will be:	Select the correct option:  A) 22  B) 23  C) 80  D) 90  E) 28
Explanation:   Let the number of hens be x and the number of cows be y.   Then, x + y = 100 .... (i)   and 2x + 4y = 220 x + 2y = 110 .... (ii)   Solving (i) and (ii) we get: x = 90, y = 10.   The required answer = 90.   Answer: 90
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A man has some hens and cows. If the number of heads be 100 and the number of feet equals 180, then the number of hens will be: