There are some goats in James farm. If they don't die for any reason James can make new farm in 6 years with baby goat and older goats. But goats die for many reason, if no baby goats are born the farm will be empty in 12 years. If new babies are born and older die in same time , how many time needed for make a new farm?
Choose the correct answer.
A) 10  B) 15  C) 5  D) 12  E) 20
Goats die in every year = 1/12   Goats born in every year = 1/6   Total growth in every year = 1/6 - 1/12 = 1/12   So James can make a new farm in = 12 years   ANSWER:12
<result>D</result>
There are some goats in James farm. If they don't die for any reason James can make new farm in 6 years with baby goat and older goats. But goats die for many reason, if no baby goats are born the farm will be empty in 12 years. If new babies are born and older die in same time , how many time needed for make a new farm?