InterviewSolution
| 1. |
A can contains a mixture of two liquids A and B in the ratio 7 : 5. When 9 litres of mixture are drawn off and the can is filled with B, the ratio of A and B becomes 7 : 9. Litres of liquid A contained by the can initially was1). 102). 203). 214). 25 |
|
Answer» Since the ratio of volume of LIQUIDS A and B is 7 : 5. Let the volume of A in mixture initially be 7X lts and volume of B in mixture initially be 5x lts Total volume in can initially = 12x lts Since 9 lts were drawn off from total mixture and same was filled by liquid B. Thus, New volume of liquid A = $(\left( {7x - \frac{9}{{12x}} \times 7x} \RIGHT))$ New volume of liquid B = $(\left( {5x - \frac{9}{{12x}} \times 5x + 9} \right))$ Given the new ratio of liquid A and B is 7 : 9. Thus, $(\begin{array}{l} \Rightarrow \frac{{7x - \frac{9}{{12x}} \times 7x}}{{5x - \frac{9}{{12x}} \times 5x + 9}} = \frac{7}{9}\\ \Rightarrow \frac{{28x - 21}}{{20x - 15 + 36}} = \frac{7}{9} \end{array})$ ⇒ 252x – 189 = 140x + 147 ⇒ 112x = 336 ⇒ x = 3 Hence the initial volume of liquid A = 7 × 3 = 21 liters |
|