150 ml of 30% sulphuric acid was added to approximate 400 ml of 12% sulphuric acid solution. Find the approximate concentration R of the acid in the mixture?	Options
A) 1/2	B) 1/3	C) 1/4	D) 1/6	E) 1/5
Do not need any computation   30%-----------21%---------12%   if volume of both sol. were equal the concentration R would be 21%=1/5, but 12% is more than 3 times   only possibility is 1/6   1/6
<result>D</result>
150 ml of 30% sulphuric acid was added to approximate 400 ml of 12% sulphuric acid solution. Find the approximate concentration R of the acid in the mixture?