the average weight of 30 boys sitting in a bus had some value . a new person added to them whose weight was 40 kg only . due to his arrival , the average weight of all the boys decreased by 2 kg . find the average weight of first 30 boys ?
30 x + 40 = 31 ( x â € “ 2 ) x = 102 e
add(add(40, add(30, 30)), 2)