Sue got a lot of money for graduation from a mysterious, rich aunt that she’d never known she had. Her first thought was AUDIO EQUIPMENT, but then she figured she really ought to put it away for a rainy day. She divided it into two parts. One part had $250 more than the other part. She invested the smaller part at 6% interest, and the larger part at 8%. A year later, the total interest she had accumulated was $72.50. How much money did she get from her mysterious, rich aunt for graduation in the first place?

Call the two parts (

Then

*x*) and (*x*+ $250).Then

0.06(

0.06

0.14

We can see that the first part was $375 and we can find the second part by substitution.

(

*x*) + 0.08(*x*+ $250) = $72.500.06

*x*+ 0.08*x*+ $20 = $72.500.14

*x*= $52.50*x*= $375We can see that the first part was $375 and we can find the second part by substitution.

(

*x*+ $250) = $375 + $250 = $625Total inheritance = $375 + $625 = $1000

We should all be so lucky…