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?

I was actually able to put this one out to pasture without writing a program.

Mooooving right along...A brown cow is eight fifths as productive as a black cow.

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.

Let x be the milk per day of one black cow.
Let y be the milk per day of one brown cow.

5(4x) + 5(3y) = 4(5y) + 4(3x)
20x + 15y = 20y + 12x
8x = 5y
y = (8/5)x

Posted by Penny on 2004-09-05 19:28:56