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 one cow?	Choose the correct choice from the following
A) 2178 lt	B) 3697 lt	C) 6583 lt	D) 4370 lt	E) 5548 lt
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%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, =&gt; one cow produced 4370 litres   correct answer is 4370 lt)4370 lt
<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 one cow?