Question
Average weight of all the people in a group is 55 kg.
When two people of weight 63 kg and 77 kg left the group, average weight reduces by 1.5 kg. Find the number of people in the group now.Solution
Let the number of people initially be 'n'.
So, 55n - 53.5 × (n - 2) = 63 + 77
Or, 55n - 53.5n + 107 = 140
Or, 1.5n = 33
Or, 'n' = 22
Required number of people = 22 - 2 = 20
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