Stressfree

1   weight 6 ping pongs with another 6 ping pongs. see which side is heavier
% h. C( A, J. D& n5 k8 }2 j8 ?! I2   spilt the heavier side ping pongs in half and weight against each other
4 ?% E5 c6 C: z! ]3   weiht either ping pongs one on one then you will know which is the heavy one.