You invested $ 8000 between two accounts paying 6 % and 7 % annual​ interest, respectively. If the total interest earned for the year was $ 530 comma how much was invested at each​ rate?

Answer 1

530/8000 = combined return = 53/800 = 6.625%

more will be invested at 7 than 6% because 6.625 is closer to 7

7-6.625= .375

6.625= .625

625/375 = 25/15=5/3

5/3 as much will be invested at 7 as at 6%

5/3 = x/(8000-x)

3x = 40,000 -5x

8x = 40,000

x = $5,000 at 7%, $3,000 at 6%

530 = .07x + .06(8000- x)

.01x = 530 -480 = 50'

x =50/.01 = $5,000 at 7%

8000-x = $3,000 at 6%