In the beginning, 17% of the 28 milliliters of liquid, which is 4.76
milliliters, is pure alcohol.  The rest is water.

Then we add x milliliters of water.

Now we have 28+x milliliters of liquid of which the 4.76 milliliters 
of pure ancohol is now only 14% of.  So,

The 4.76 ml. of pure alcohol = 14% of the 28+x milliliters of liquid.

   4.76 = .14(28 + x)

Solve that and get x=6 as the number of milliliters of water to add.

Edwin