Find 4 + 7 + 10 + 13 + 16 + . . . up to 20 terms	Choose the correct choice from the following answers:
A) 650	B) 640	C) 630	D) 620	E) 610

Rationale: a = 4 d = 7 – 4 = 3 sum of first 20 terms , s 20 answer is a
Answer: A