A Flask contains a mixture of AB in the ratio 5:2. When 20 L of Mixture is replaced with liquid B, ratio becomes 4:1. How many liters of liquid A was present in mixture initially. Choose the correct choice from the following answers:
A) 10
B) 22
C) 15
D) 30
E) 8
Let the volume of the initial total mixture was V. When 20L of mixture is removed the volume becomes (V - 20). The concentration stays 5:2.   Next step, when you add 20 litres of B, the amount of A does not change.   So   Amount of A in original mix = Amount of A in final mix   C1 * V1 = C2 * V2   (5/7)*(V - 20) = (4/5)*V   V = 30.8   So volume of A in initial mixture was   (5/7) * 30.8= 
<gadget id="calculator">  (5/7) * 30.8</gadget>
<output>22</output>
22 litres   Answer 22
<result>B</result>
A Flask contains a mixture of AB in the ratio 5:2. When 20 L of Mixture is replaced with liquid B, ratio becomes 4:1. How many liters of liquid A was present in mixture initially.