The radiator of a car can contain 10 gal of liquid. If it is half full with a mixture having 60% antifreeze and 40% water, how much more water must be added so that the resulting mixture has only.


So there is 6g of antifreeze.

Let's find out when 6g is 40%

(6/40) * 100 = 15

15 - 10 = 5

5g of water must be added to mixture is contain 40% of antifreeze.

But answer in the book says 5/2g.
How?