1.64g of a mixture of cac03 and mgc03 was dissolved in 50ml of 0.8M hcl. The excess of acid required 16ml of 0.25M naoh for neutralization. Calculate the percentage of cac03 and mgc03 in the sample

Steve helps me step by step

what was not clear in the explanation given here?

http://www.jiskha.com/display.cgi?id=1387643326

Maybe someone else can figure out a different viewpoint.