The average age of a group of n people is 14 years old. One more person aged 34 joins the group and the new average is 16 years old. What is the value of n?  Choose the correct choice from the following choices: A) 7 B) 8 C) 9 D) 10 E) 11

Rationale: "14 n + 34 = 16 ( n + 1 ) 2 n = 18 n = 9 the answer is c ."
Answer: C