In five days, four black cows and three brown cows give as much milk, as five brown cows and three black cows would give in four days.
Which color cows are the best milk producers?
Let the amount consumed by five days, four black cows and three brown cows be A which is equivalent
to the amount consumed by five brown cows and three black cows in four days.
Let L = Amount consumed by each black cow in one day, and:
N = Amount consumed by each brown cow in one day
Then, by the problem:
5(4L + 3N) = 4(3L + 5N)
-> 8L = 5N
-> N/L = 8/5 > 1
-> N > L
Accordingly, the per day yield of milk from each brown cow is greater when compared to the yield per day from its black counterpart, and consequently, the brown color cows are the best milk producers.
Edited on February 28, 2008, 5:56 am
Puzzle Solution
