Stressfree

1   weight 6 ping pongs with another 6 ping pongs. see which side is heavier+ |; `/ m7 j" A% a/ s; Y. _. r
2   spilt the heavier side ping pongs in half and weight against each other, U; {' w- O' B( r- I& W2 Q0 b1 ?7 g3 T
3   weiht either ping pongs one on one then you will know which is the heavy one.