SOLUTION: If $50,000 is invested part at 9% and the rest at 12%, and the interest from one year is $4,800. How much was invested at 12%?

Question 1108639: If $50,000 is invested part at 9% and the rest at 12%, and the interest from one year is $4,800. How much was invested at 12%?
Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
Let = amount invested @ 9%
= amount invested @ 12%
-----------------------------------------
Let = interest for 1 yr from 9% investment
= interest for 1 yr from 12% investment
-------------------------------------------------
Use simple interest formula
(1)
(1)
and
(2)
(2)
(2)
(2)
(2)
----------------------------------
( 1 )
Plug (1) into (2)
(2)
(2)
(2)
(2)
and
(1)
(1)
and

----------------------------------
$10,000 was invested @ 12%
----------------------------------
check:
(1)
(1)
(1)
and
(2)
(2)
(2)
(2)
OK

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