The average weight of the people in a group was calculated.  Aaron, who weighs $$45\text{kg}$$, joined the group and the average changed to $$61\text{kg}$$.  Then Ben, who weighs $$71\text{kg}$$, joined the group after Aaron. The average changed to $$62\text{kg}$$.  What was the average weight of the group before Aaron and Ben joined them? 
Overseas Competition->Knowledge Point->Counting Modules->Statistics and Probability Overseas Competition->Knowledge Point->Word Problem Modules->Average Problems ->Questions Involving Average->Questions Involving Average (ordinary type)