Question 883604
Are you asking for 4 Liters of pure (100%) antifreeze?


Here is a lesson which fits your (this) form:
<a href="http://www.algebra.com/my/Two-Part-Mixture-with-one-material-quantity-unknown.lesson?content_action=show_dev">Two-Part Mixture: One material Quantity Unknown</a>


If you find a result, check the result in your original equation to find if it works or not.


To start,
Let x = volume of water to add.
{{{4*100/(4+x)=60}}}, and you would only have trouble for not understanding the equation.  If you do understand the equation, then the steps to solving for x should be no trouble.