I need some help with a conservation of mass equation.?

Question

Here is the problem from my book:

Aluminum metal reacts with bromine. the reaction produces aluminum bromide. A sample of 27.0 g of aluminum yields 266.7 g of aluminum bromide. how many grams of bromine react with 15.0 g of aluminum?

Now i don't exactly want the answer to the problem (although that would be nice haha), i just need help on how to do the problem. i can't remember how to set up the problem to get the answer so any help would be appreciated.

Answer 1

One could set up a proportion

27.0 g aluminum/266.7 g aluminum bromine = 15.0 g aluminum/ x grams of aluminum bromine.  

Solve that proportion for x  then  subtract the 15.0 g of

aluminum present to determine the number of grams of

bromide.    

Thus once you solve for x, answer is  x-15.0

This will get you the answer.