Answer:
There must be added 6.25L of a 12% salt solution
Step-by-step explanation:
We add ‘x’ litres of 12% salt solution into 10 litres of 25% salt solution, so resulting in “x+10” litres of 20% salt solution.
x litres of 12% salt solution + 10 litres 25% salt solution = (x+10) litres 20% salt solution
this gives us the formula:
x(12) + 10(25) = (x+10)20
12x + 250 = 20x +200
-8x = -50
x=6.25
Therefore add 6.25 litres of 12% salt solution to 10 litres of 25% salt solution to obtain a 20% salt solution.
