220 metres long yard, 21 trees are palnted at equal distances, one tree being at each end of the yard. What is the distance between 2 consecutive trees	Choose the correct choice from the following choices: A) 10 B) 12 C) 14 D) 11 E) 17

Rationale: "21 trees have 20 gaps between them , required distance ( 220 / 20 ) = 11 d"
Answer: D