Question
Average weight of all the people in a group is 66 kg.
When two people of weight 72 kg and 84 kg left the group, average weight reduces by 1.2 kg. Find the number of people in the group now.Solution
Let the number of people initially be 'n'.
So, 66n - 64.8 × (n - 2) = 72 + 84
Or, 66n - 64.8n + 129.6 = 156
Or, 1.2n = 26.4
Or, 'n' = 22
Required number of people = 22 - 2 = 20
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