Question

a woman has $28,000. part is invested for one year in a certificate of deposit paying 7% interest, and the remaining amount in cash management fund paying 9%. after 1 year, the total interest on the two investments is $2,200. how much is invested at each rate

Answer 1

Answer:

Amount invested at 7% = 16000

Amount invested at 9% = 12000

Step-by-step explanation:

Let x be the amount invested at 7% and y be the amount invested at 9%.

Since the total amount invested is $28000, therefore, we can set up the first equation as:

$x+y=28000$

Secondly, we are give that sum of two investments is $2200. Therefore, we can write the second equation as:

$0.07x+0.09y=2200$

Now we need to solve these two equations to get the values of x and y.

First of all, we multiply the second equation with 100 in order to get rid of decimal values.

$(0.07x+0.09y)*100=2200*100\\7x+9y=220000$

Let us use substitution method here. First of all we will solve for y from first equation and plug that into second equation.

$y=28000-x$

$7x+9(28000-x)=220000\\7x+252000-9x=220000\\-2x=-32000\\x=16000$

Therefore, amount invested at 7% is $16000 and amount invested at 9% is 28000-16000=$12000.