Stressfree

1   weight 6 ping pongs with another 6 ping pongs. see which side is heavier
6 p: z4 g. t( [! V3 Z; X7 K. B, V2   spilt the heavier side ping pongs in half and weight against each othertvb now,tvbnow,bttvb. S- j, F2 e( h$ O6 Q% i  g: c
3   weiht either ping pongs one on one then you will know which is the heavy one.