Answer:
4 liters of 5% solution and 16 liters of 17.5% solution we need.
Step-by-step explanation:
Let us assume that x liters of 5% solution and y liters of 17.5% solution are taken.
So, x + y = 20 ........ (1)
As the final solution is of 15%, so we can write
⇒ 5x + 17.5y = 300 ......... (2)
Now, solving equations (1) and (2) we get,
17.5y - 5y = 200
⇒ 12.5y = 200
⇒ y = 16 liters
Hence, x = 20 - y = 4 liters.
Therefore, 4 liters of 5% solution and 16 liters of 17.5% solution we need. (Answer)