if the average ( arithmetic mean ) of the 4 numbers 3 , 16 , 33 , and ( n + 1 ) is 20 , then n =  Pick:
A) 19 B) 20 C) 21 D) 27 E) 29

Rationale: 3 + 16 + 33 + n + 1 = 20 x 4 = 80 = > n + 53 = 80 = > n = 27 answer d
Answer: D