The average weight of 20 persons sitting in a boat had some value. A new person added to them whose weight was 45 kg only. Due to his arrival, the average weight of all the persons decreased by 5 kg. Find the average weight of first 20 persons?	Choose the correct choice from the following choices.
A) 55	B) 56	C) 57	D) 58	E) 60

Rationale: "20 x + 45 = 21 ( x – 5 ) x = 60 answer : e"
Answer: E