A housewife has 11 litre of solution that contains sodium carbonate solution and benzene solution in the ratio 3 : 1. She adds 250 ml of 3 : 2 solution of sodium carbonate and benzene solution to it and then uses 250 ml of the combined mixture to make strong organic solution How much of pure sodium carbonate solution is she left with?
Choose the most appropriate option
A) 1000 ml  B) 912.5 ml  C) 750 ml  D) 720 ml  E) 630 ml
ln a mixture of 1,000 ml sodium carbonate : benzene solution = 3 : 1.   Hence, sodium carbonate: 750 ml benzene solution 250 ml   A 250 ml of 3 : 2 solution contains 150 ml sodium carbonate solution and l00ml benzene solution.   Total sodium carbonate solution = 900 ml, total benzene solution = 350 ml   After using 250 ml to make strong organic solution , sodium carbonate solution used   = 250/1250 x 900 = 180 ml   pure sodium carbonate solution left = 900 -180= 
<gadget id="calculator">900 -180</gadget>
<output>720</output>
720ml   ANSWER:720 ml
<result>D</result>
A housewife has 11 litre of solution that contains sodium carbonate solution and benzene solution in the ratio 3 : 1. She adds 250 ml of 3 : 2 solution of sodium carbonate and benzene solution to it and then uses 250 ml of the combined mixture to make strong organic solution How much of pure sodium carbonate solution is she left with?