The first year, two cows produced 8100 litres of milk. The second year their production increased by 15% and 10% respectively, and the total amount of milk increased to 9100 litres a year. How many litres were milked from each cow each year? Choose the correct choice from the following answers.
A) 4370, 4730 liters and 3800, 4300 liters B) 4300, 3800 liters and 4730, 3800 liters C) 4730, 3800 liters and 4300, 3800 liters D) 3800, 4300 liters and 4370, 4730 liters E) 4300, 4370 liters and 3800, 4730 liters
Let x be the amount of milk the first cow produced during the first year. Then the second cow produced (8100−x) litres of milk that year. The second year, each cow produced the same amount of milk as they did the first year plus the increase of 15% or 10%.   So 8100+15100⋅x+10100⋅(8100−x)=9100   Therefore 8100+320x+110(8100−x)=9100   120x=190   x=3800   Therefore, the cows produced 3800 and 4300 litres of milk the first year, and 4370 and 4730 litres of milk the second year, respectively.   So answer is 3800, 4300 liters and 4370, 4730 liters.
<result>D</result>
The first year, two cows produced 8100 litres of milk. The second year their production increased by 15% and 10% respectively, and the total amount of milk increased to 9100 litres a year. How many litres were milked from each cow each year?