2015 CEMC Gauss (Grade 8) Problems/Problem 15
Revision as of 18:52, 13 October 2025 by Anabel.disher (talk | contribs) (Created page with "== Problem== Two puppies, Walter and Stanley, are growing at different but constant rates. Walter’s mass is <math>12</math> kg and he is growing at a rate of <math>2</math>...")
Problem
Two puppies, Walter and Stanley, are growing at different but constant rates. Walter’s mass is 
kg and he is growing at a rate of 
kg/month. Stanley’s mass is 
kg and he is growing at a rate of 
kg/month. What will Stanley’s mass be when it is equal to Walter’s?
Solution 1
We can create functions. Let 
represent Stanley's mass after 
months and 
represent Walter's mass after months.
Since Stanley is originally kg and is growing at a rate of kg per month, we have:
We can now see at what value these intersect at by setting the equations equal to each other:
We can now plug-in 
into one of the equations (either one would work) to see what weight Stanley would have, as both would be equal:
~anabel.disher
