The average runs scored by a batsman in 20 matches is 40. In the next 30 matches the batsman scored an average of 20 runs. Find his average in all the 50 matches? Choose the correct choice from the following answers:
A) 31
B) 46
C) 28
D) 13
E) 12

Rationale: "total score of the batsman in 20 matches = 800 . total score of the batsman in the next 30 matches = 600 . total score of the batsman in the 50 matches = 1400 . average score of the batsman = 1400 / 50 = 28 . answer : c"
Answer: C