The average runs scored by a batsman in 15 matches is 30. In the next 20 matches the batsman scored an average of 15 runs. Find his average in all the 30 matches?  Pick.
A) 31.56  B) 25.65  C) 21.43  D) 28.36  E) 27.96

Rationale: total score of the batsman in 15 matches = 450 . total score of the batsman in the next 20 matches = 300 . total score of the batsman in the 35 matches = 750 . average score of the batsman = 750 / 35 = 21.43 . answer : c
Answer: C