The sport is called the "Shot Put". The shot is 'put' as far from the contestant as possible. So the question is, "How heavy is the shot in the 'shot put event' for boys aged 15?" The answer is 12 pounds.
Shot put is to try to throw a heavy ball the longest distance
In general a shotput weights 16lbs in juniors (schools) - it weighs 12 lbs and in sub-juniors division - it weights 8 lbs
16lbs. for mens competition.
I would describe the shot put as a round and slightly heavy metal or hard plastic ball.
too big for you