Using a given cake recipe, one can make 1 1/2 cakes using 3 1/2 cups flour. How much flour must be used to make one whole cake?

Question

I am not so great at word problems, I am trying to understand what I need to do here. Addition?

Answer 1

a problem like this is a proportion problem:
1.  look at the given information: 3 1/2 cups of flour will make 1 1/2 cakes
2.  but you only want to make one cake!  so how much flour do you need?
         

solution:

let x = the amount of flour needed for one cake. 
set up a proportion (a comparison of two ratios)

    3 1/2 cups flour is to 1 1/2 cakes as x cups flour is to 1 cake

another way to write this is

     7/2:3/2::x:1

but the easiest way to set it up once you understand the concept is this:

     (7/2)/(3/2) = x/1

     cross multiply and solve for x.  you should get 7/3 cups flour or 2 1/3 cups

 

hope this helped

Answer 2

3/2 cakes.  requires =7/2 cups of flour

 

 

So flour needed for one cake = (7/2)*2/3

                                           =7/3

                                            cups of flour