Question 1164206:  Paul has $70,000 to invest. His intent is to earn 15% interest on his investment. He can invest part of his money at 8% interest and part at 18% interest. How much does Paul need to invest in each option to make a total 15% return on his $70? 
 Found 2 solutions by  solver91311, greenestamps: Answer by solver91311(24713)      (Show Source):  Answer by greenestamps(13215)      (Show Source): 
You can  put this solution on YOUR website! 
  
The setup for solving the problem shown by the other tutor is a good example of how to solve a problem using formal algebra.  You should understand how to use that method.
  
If a formal algebraic method is not required, here is a solution method that is almost trivial.
  
The target return rate, 15%, is 7/10 of the way from 8% to 18%.  (8 to 15 is a difference of 7; 8 to 18 is a difference of 10.)
  
Therefore, 7/10 of the total needs to be invested at the higher rate.
  
ANSWER: 7/10 of the $70,000, or 49,000, at 18%; the other $21,000 at 8%.
  
CHECK: 
0.18(49000)+0.08(21000) = 8820+1680 = 10500 
0.15(70000) = 10500
  
 
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