James divides rp 150,000,000 out over 3 bank accounts; bank a,b and c. bank account a earns 5% annual interest while bank account b earns 7% annual interest. at the end of the year, james receives rp 2,275,000 interest from bank a, rp 4,900,000 from bank b. unfortunately, james lost the bank details of bank c, and only has the information of his balance after receiving the interest, which is currently at rp. 35,535,000. what is the interest rate of bank c?

James divides rp 150,000,000 out over 3 bank accounts; bank a,b and c. bank account a earns 5% annual interest while bank account b earns 7% annual interest. at the end of the year, james receives rp 2,275,000 interest from bank a, rp 4,900,000 from bank b. unfortunately, james lost the bank details of bank c, and only has the information of his balance after receiving the interest, which is currently at rp. 35,535,000. what is the interest rate of bank c?

Jawaban:

Penjelasan:

BANK A

a x 5/100 = 2.275.000

5a = 227.500.000

a = 227.500.000/5

a = 45.500.000 (total sum of money save at bank a)

BANK B

b x 7/100 = 4.900.000

7b = 490.000.000

b = 490.000.000/7

b = 70.000.000 (total sum of money save at bank b)

BANK C

total sum of money save at bank c = 150.000.000 – (a+b)

c = 150.000.000 – (45.500.000 + 70.000.000)
c = 150.000.000 – 115.500.000

c = 34.500.000

the interest of bank c is = 35.535.000 – 34.500.000 = 1.035.000

c x α/100 = 1.035.000

34.500.000 x α/100 = 1.035.000

34.500.000α = 103.500.000

α = 103.500.000/34.500.000

α = 3

so, the interest rate of bank C is 3%