Subbota wrote:the five together weigh(228+230+236+238+242+244+246+250+252+258)/4=606
Know that you know that,
You also know 258 must be the sum of the two heaviest grundos.
You also know 228 must be the sum of the two lightest grundos.
606-228-258 = 120
120 is the weight of the middle grundo.
That should be a start.