easy, one minutes i solve the problem
) _' ]1 \7 z) x8 F: t1 ~divide into half, mean 6/ 6
6 u/ N: i& [* q& h5.39.217.77take the heavier 6 ping pong
6 G7 U* R! ~- X$ X5.39.217.77divide into 3/3, take the heavier 3
# R- Q( c r* C; Q3 A/ |+ J. [6 @9 A* ptake the the other 3 that have the equal weight, switch each to measure, the most important things is labeling the ping pong so that we can recognize |