| 
 
 
| Question 153650:  Please help me solve: Susan Marciano invested part of her $18,000 bonus in a fund that paid an 8% profit and invested the rest in stock that suffered a 3% loss. Find the amount of each investment if her overall net profit was $780.
 They want to know: The amount invested at 8% is:
 and the amount invested in stock is:
 Answer by orca(409)
      (Show Source): 
You can put this solution on YOUR website! Let x be the amount invested in funds that earned 8%. Then the amount invested in stock that suffered 3% loss is 18,000 - x.
 The profit from investment in funds is 8%x
 The loss from investment in stock is 3%(18,000 - x).
 The net profit is 8%x - 3%(18,000 - x).
 As the net profit given in the problem is $780, we have:
 8%x - 3%(18,000 - x) = 780
 Solving for x, we have:
 8x - 3(18,000 - x) = 78000   (multiply both sides by 100)
 8x - 54000 + 3x = 78000
 11x = 132000
 x = 132000/11
 x = 12,000
 So
 the amount invested in funds that earned 8% is 12,000.
 the amount invested in stock that suffered 3% loss is 18,000 - x = 18000 - 12000 = 6,000.
 
 | 
  
 | 
 |