A grocery shop has a sale of Rs. 6635, Rs. 6927, Rs. 6855, Rs. 7230 and Rs. 6562 for 5 consecutive months. How much sale must he have in the sixth month so that he gets an average sale of Rs. 6500?  Choose the correct choice from the following answers:
A) 4857  B) 4184  C) 4012  D) 4791  E) 5291

Rationale: let the sale in the sixth month = x then ( 6635 + 6927 + 6855 + 7230 + 6562 + x ) / 6 = 6500 = > 6635 + 6927 + 6855 + 7230 + 6562 + x = 6 × 6500 = > 34209 + x = 39000 = > x = 39000 − 34209 = 4791 answer : d
Answer: D