Answer: 2Liters
Step-by-step explanation:
The expression used will be :
![M_1V_1+M_2V_2=M_3V_3](https://img.qammunity.org/2021/formulas/chemistry/high-school/t4k6q1y1f8urtoei9npphqzztuukhntenw.png)
where,
= concentration of first antifreeze= 60%
= concentration of second antifreeze= 10%
= volume of first antifreeze = x L
= volume of second antifreeze = 8 L
= concentration of final antifreeze solution= 20%
= volume of final antifreeze = (x+8) L
Now put all the given values in the above law, we get the volume of antifreeze added
![60* x+10* 8=20* (x+8)](https://img.qammunity.org/2021/formulas/chemistry/high-school/5nejas4jbmiahyb2q0mhs627titvzcemxn.png)
![x=2L](https://img.qammunity.org/2021/formulas/chemistry/high-school/lfmf81jukvy2l8rf0bvyg1q5ugzi27c24r.png)
Therefore, the volume of 60% antifreeze solution that must be added is 2L