A man invests some money at 5%, and $49,000 more than three times the amount at 11%. The total annual interest earned from the investment is $51,370. How much did he invest at each amount?

1 Answer
Dec 20, 2017

$121,000 was invested at 5%

$412,000 was invested at 11%

Explanation:

There is a given relationship between the two amounts, so you can define them using one variable.

Let the amount at 5% be x.
Therefore the larger amount at 11% is 3x+49,000

Now form an equation - you know the total amount of interest is 51,370

'Interest at 5% + Interest at 11% = 51,370

5/100xx x + 11/100xx(3x+49000) = 51370" "larr xx 100

5x +11(3x+49,000) = 51,370

5x +33x+539,000 = 5,137,000

38x = 5,137,000-539,000

38x = 4,598,000

x=121,000

121xx3+49000 = 412,000