Juanita has exist28000 to invest in two accounts that pay si

Juanita has exist28,000 to invest in two accounts that pay simple interest on an annual basis. One account pays 6% in simple interest, and the other pays 3% simple interest. How much would she have to invest in each account to earn a total interest of exist1, 290 after one year? She would have to invest exist at 6% simple interest and at exist 3% simple interest. (Simplify your answers.)

Solution

Let x = the amount invested at 6% and

y = the amount invested at 3%.

Then

x + y = 28000

y = 28000 - x ... (1)

0.06x + 0.03y = 1290 ...(2)

Substitute the value of y from (1) into (2),

0.06x + 0.03(28000-x) = 1290

0.06x + 840 - 0.03x = 1290

0.03x + 840 = 1290

0.03x = 1290 - 840

0.03x = 450

x = 450/0.03 = 15000

Substitute this in (1), y = 28000 - 15000 = 13000

So, the amount invested at 6% = x = $15,000

The amount invested at 3% = y = $ 13, 000