I have 300 coins all are dimes or quarters that equal 67.50 what is the algebraic solution

Question

There are 300 coins in the bank..they are all quarters and dimes.  They equal 67.50  How many dimes and quarters make up this amount.  What is the algebraic equation?

Answer 1

300 = q + d           67.50 = .25q + .10d

 

you know that there are a certain number of each coins that add up to equal 300 coins in total .  you also know that there are a certain amount of each coin that totals out to be 67.50 so you use the value of each coin with the variables to show that there is an unknown amount of each at the present time. ex: we know that there are quarters that make up a certain dollar amount of the 67.50 , we just do not know the number of quarters so we use the dollar value ( .25 ) plus the variable ( q ) to show that the number is unknown. same for the dimes.