In a coconut grove, (x + 2) trees yield 60 nuts per year, x trees yield 120 nuts per year and (x – 2) trees yield 180 nuts per year. If the average yield per year per tree be 100, find x. Options.
A) 3  B) 4  C) 5  D) 6  E) None of the above
(x+2)×60+x×120+(x−2)×180/(x+2)+x+(x−2)=100   ⇒ 360x−240/3x = 100   ⇒ 60x = 240 ⇒ x = 4   Answer None of the above
<result>E</result>
In a coconut grove, (x + 2) trees yield 60 nuts per year, x trees yield 120 nuts per year and (x – 2) trees yield 180 nuts per year. If the average yield per year per tree be 100, find x.