In a mixture of 45 litres, the ratio of acid to base is 3 : 2. How much base must be added to make the ratio 9: 11? Pick:
A) 10 lts
B) 15 lts
C) 17 lts
D) 20 lts
E) 22 lts
Let M = 3K,W = 2K   Thus, 3K + 2K = 45   =&gt; K=9   =&gt; acid = 27 litres and base = 18 litres.   Now suppose x litres of base is added to the mixture such that   27/(18 + X) = 9/11   =&gt;162 +9X = 297   =&gt; 9X = 135   =&gt; X = 15   ANSWER:15 lts
<result>B</result>
In a mixture of 45 litres, the ratio of acid to base is 3 : 2. How much base must be added to make the ratio 9: 11?