Grams of tin and lead
An alloy is 7 parts tin and 3 parts lead. How many grams of each are in 40g of the alloy? Let x= the number of grams of tin in the 40g of the alloy. Next, we note that there are 8 total parts of the alloy, of which 7 are tin. Thus 7 is to 8 as x is to ___. How many grams of tin and lead are there and what is the ratio?