word problem

Question

Katie invested a total of $7000 , part at 33 % simple interest and part at 44 % simple interest. At the end of 1 year, the investments had earned $252 interest. How much was invested at each rate?

Answer 1

Simple interest:  I = prt

 

If we invest $x at 33% then we invest (7000-x) at 44%

 

252 = x(0.33)(1) + (7000-x)(0.44)(1)

 

252 = .33x - .44x + 3080

 

-2828 = -.11x

 

Just divide both sides by -0.11 to get the amount invested

at 33%.   Subtract that amount from 7000 to get the

amount invested at 44%