A solution of phenyl and water is 28 litres, with phenyl and water in ratio 4 : 3. 21 litres phenyl-water solution which has phenyl to water ratio as 2 : 1 is added to the 28 litres phenyl-water solution. Again 51 litres phenyl-water solution that has phenyl to water ratio as 9 : 8 is added to this. What is ratio of water to phenyl in the final mixture?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e 43 : 57.
Initial 28 L @ 4 : 3 ⇒ phenyl 16 L, water 12 L
Add 21 L @ 2 : 1 ⇒ phenyl 14 L, water 7 L
Add 51 L @ 9 : 8 ⇒ phenyl 27 L, water 24 L
Totals: phenyl = 16 + 14 + 27 = 57 L; water = 12 + 7 + 24 = 43 L
Required ratio (water : phenyl) = 43 : 57