Stressfree

1   weight 6 ping pongs with another 6 ping pongs. see which side is heavier公仔箱論壇+ o( s" k+ H* d" V" @
2   spilt the heavier side ping pongs in half and weight against each other
, x* s2 U; U0 h2 @tvboxnow.com3   weiht either ping pongs one on one then you will know which is the heavy one.