Suraj has a certain average of runs for 9 innings. In the 10th innings he scores 200 runs thereby increasing his average by 8 runs. What is his average after the 10th innings?
Choose the correct choice:
A) 149
B) 190
C) 128
D) 178
E) 190

Rationale: "to improve his average by 8 runs per innings he has to contribute 9 x 8 = 72 runs for the previous 8 innings . thus , the average after the 9 th innings = 200 - 72 = 128 . answer : c"
Answer: C