Question 1058330
If 12 people have an average of 68 kg, then their total weight is 12 x 68, or 816 kg. 3 leave, leaving an average of 66.5 kg x 9 people, or 598.5 total kgs. 
(816-598.5)/3=72.5 as the average weight of the members who left the group. &#9786;&#9786;&#9786;&#9786;