Rule:

To break a quantity Q down into parts in the ratio of 

      a:b:c

multiply Q by the fractions 

, , and .

---------------------------------

We wish to break $464 down into parts in the ratio of
     
     3:5:8

so we multiply $464 by the fractions:

, , and ,

or

, , and 

or 

, , and 
 
When we multiply we get:

,

×$464, ×$464, and ×$464

            $87, $145, and $232
  
So Mary contributed $87, Bob contributed $145, and Dylan contributed $232.

Edwin