A cricketer whose bowling average is 12.4 runs per wicket takes 5 wickets for 26 runs and thereby decreases his average by 0.4. The number of wickets taken by him till the last match was:  Options:
A) 64  B) 72  C) 80  D) 85  E) None of the above
Let the number of wickets taken till the last match be x.   Then,   12.4x+26/x+5= 12 ⇒ 12.4x + 26 = 12x + 60   ⇒ 0.4x = 34 ⇒ x = 34⁄0.4 = 340⁄4 = 85.   Answer 85
<result>D</result>
A cricketer whose bowling average is 12.4 runs per wicket takes 5 wickets for 26 runs and thereby decreases his average by 0.4. The number of wickets taken by him till the last match was: