Math

 

I'm thinking of two numbers. One number is 8 times as big as the other. The difference between the two numbers is 28. What is the sum of the two numbers?   

 

Let N stand for the smaller number  

and 8N stand for the number that's 8 times as big 

 

so                        8N – N  =  28 

                                  7N  =  28 

                                    N  =  4  

 

then                          8N  =  32  

 

so their sum is     4 + 32  =  36  

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