Greg invested $11,000 in two accounts. • The first account pays 5% interest per year.
• The second account pays 8% interest per year.
Greg earned a total of $752.50 in interest at the end of the first year.
How much did Greg invest in the 5% account?

A) 6750
B) 3415
C) 5500
D) $4250

D; $4,250

Step-by-step explanation:

Here, we want to know the amount that was invested in the 5% account

We proceed as follows;

Let the amount invested in the 5% interest account be $a and the amount invested in the 8% interest account be $b

We have it that the total investment amount is $11,000

Mathematically, since total is 11,000; we can add a and b to give this

a + b = 11,000 •••••••••(i)

Now, let us work with the interests

Interest earned will be;

Percentage of interest * Amount invested

For the 5% interest account, the interest earned will be;

5/100 * a = 5a/100 = 0.05a

For the 8% interest account , the interest earned will be;

8/100 * b = 0.08b

By adding the interests on both account, we can get the total amount of interest earned

We can have this as;

0.05a + 0.08b = 752.50 •••••(ii)

From equation i above;

b = 11,000 - a

Substitute this into ii

0.05a + 0.08(11,000-a) = 752.5

0.05a+ 880 - 0.08a = 752.5

0.08a-0.05a = 880-752.5

0.03a = 127.5

a = 127.5/0.03

a = $4,250

7

step-by-step explanation:

7. d. 64

8. i. 32

9. c. 125

10. j. none of the above

11. d. 81

12. i. 216

13. e. none of the above

14. g. 240

15. e. none of the above

16. g. 32

17.   e. none of the above