The average of 6 observations is 14. A new observation is included and the new average is decreased by 1. The seventh observation is?  Choose the correct option.
A) 1 B) 3 C) 5 D) 6 E) 7

Rationale: "let seventh observation = x . then , according to the question we have = > ( 84 + x ) / 7 = 13 = > x = 7 . hence , the seventh observation is 7 . answer : e"
Answer: E