A cricketer, whose bowling average was 12.4 runs/wicket takes 5 wickets for 22 runs in a match, thereby decreases his average by 0.4. The number of wickets, taken by him before this match was:
A rectangular playground ground of length 125 m and width 75 m, has a walking strip of width 3 m in the middle of the ground, along the longer side. What is the area of the ground without the walking strip?