Question

Saira invested 1000. part of 8% per annum and the remainder at 9% per annum. after one year, her total interest from these investments was $84. How much did she invest at each rate

Answer 1

х dollars - part of 8% per annum ⇒ 0.08x doll. - income

(1000-x) dollars - part of 8% per annum ⇒ 0.09(1000-x) doll. - income

0.08x - 0.09(1000-x) = 84

0.08x - 90 - 0.09x = 84

0.01x = 6

x = 600

$600 - part of 8% per annum

$400 -  part of 9% per annum

Answer 2

Let's break down the problem step by step.

Let x be the amount Saira invested at 8% per annum, and (1000 - x) be the amount she invested at 9% per annum.

Interest from the investment at 8% = x * 0.08 Interest from the investment at 9% = (1000 - x) * 0.09

According to the problem, the total interest from these investments was $84:

x * 0.08 + (1000 - x) * 0.09 = 84

Now, let's solve for x:

0.08x + 90 - 0.09x = 84 -0.01x = -6 x = 600

Saira invested $600 at 8% per annum and the remainder ($1000 - $600 = $400) at 9% per annum.