A man whose bowling average is 12.4, takes 7 wickets for 26 runs and there by decreases his average by 0.4. the number of wickets taken by him before his last match is?  Select:
A) 143
B) 144
C) 145
D) 146
E) 147

Rationale: 12.4 * x + 26 = ( 7 + x ) 12 solve equation x = 145 answer : c
Answer: C