How many more?

Question

I have 8 times as many rocks as marbles.  I have 686 more rocks than marbles.  How many marbles do I have?  how many rocks?  

Answer 1

Hi J,

 

That's a heavy collection of rocks.

 

Let R = the number of rocks and M = the number of marbles

 

Let's translate the English into math. . .

 

8 times as many rocks as marbles--> 8M = R

 

686 more rocks than marbles--> R - M = 686 or 686 + M = R

                                                      Subtract            8M  = R

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

                                                                      686 - 7M = 0

686 = 7M

 

M = 98

Then R = 784

 

Plug these numbers back into the problem to make sure they work.

 

Have fun.

 

Dan