Answer
0.6L
Work Step by Step
Denote the amount of coolant that will be replaced with water by x
We will begin with 3.6L of 60% antifreeze solution and end with 3.6L
of 50% antifreeze solution. There is no antifreeze in the water that we will replace the antifreeze with (0x):
0.6(3.6-x)+0x=0.5(3.6)
2.16-0.6x=1.8
0.36=0.6x
x=0.6
