Question

Average income of 50 families is 3000 rs. of these average income of 12 families is 1800 rs . find ou the average income of remaining families

Answer 1

average income of 50 families
sum of 50 families's income/50=3000
sum of 50 families's income=150000

sum of 12 families's income/12=1800
sum of 12 families's income=21600
sum of 38 remaining families's income =150000-21600
=128400
average of 38 remaining families's income =
128400/38=3378.94rs