150 ml of 30 % sulphuric acid was added to approximate 400 ml of 12 % sulphuric acid solution . find the approximate concentration e of the acid in the mixture ?
"do not need any computation 30 % - - - - - - - - - - - 21 % - - - - - - - - - 12 % if volume of both sol . were equal the concentration e would be 21 % = 1 / 5 , but 12 % is more than 3 times only possibility is 1 / 6 d"
divide(add(divide(multiply(150, 30), const_100), divide(multiply(400, 12), const_100)), add(150, 400))