400g of 20%,240g of 43%and350g of 66% sulfuric acid are mixed .how much watershould be added to make a 10% solution of sulfuric acid?

[0.2*400+.43*240+0.66*350] =414.2 g of sulfuric acid

[400 + 240 + 350] =990 g of sulfuric acid mixture

990 - 414.2 =575.8 g water content of 990 mixture.

414.2 = 0.10 * [575.8 + W], solve for W

W =3,566.2 g or ml of water to make 10% solution of sulfuric acid.