Question is actually in the description

Question

If I make two 1 year investments, one at 5% interest and the other at 6%, and at the end of the year my total accrued interest for both is 215$, how much did I initially invest? The 5% investment was $1000 more that the one I made at 6%

Answer 1

 

 

Let  x  represent the smaller investment

       

Then:

   x + 1000 = larger investment

 

Interest on smaller + interest on larger = 215  (given), in terms of 'x' this is:

 (0.05)(x + 1000) + (0.06)(x) = 215

 

 0.05x + 50 + 0.06x = 215     (carried the 0.05 into paren's)

                     0.11x =  165    (combined 'x' terms on left, and subtracted 50 from both sides)

 

                            x = 165/0.11 = 1500

 

The total investment was smaller+larger, or 1500 + (1000+1500) = 4000

 

 

Check:  (2500)*0.05 + (1500)*0.06 = 215  (ok)