## anonymous 4 years ago Match the information about interest earned with the principal amount invested. Remember the equation for calculating simple interest is I equals p times r times t . seventy-two dollars over 3 years at an interest rate of three percent sixty-six dollars over 2 years at an interest rate of three percent seventy-two dollars over 2 years at an interest rate of four percent seventy-two dollars over 3 years at an interest rate of two percent A. p equals nine hundred dollars B. p equals one thousand two hundred dollars C. p equals one thousand one hundred d

1. Mertsj

Did you try this?

2. Mertsj

the first one would be interest earned is 72, principal we have to find, rate is .03 and time is 3 years.

3. Mertsj

$72=P(.03)(3)$

4. Mertsj

P=800

5. Mertsj

Why do you only have 3 answers for 4 problems?

6. anonymous

I put the last one but it wont show it was ( D. p equals eight hundred dollars )

7. Mertsj

Can you try the next one and tell me what you get and I will check it.

8. anonymous

66(.3)(2) i did this but i got 39.6 :\

9. Mertsj

$66=P(.03)(2)$$\frac{66}{(.03)(2)}=P$ $1100=P$

10. anonymous

am I adding the (.03) (2) together and then dividing it by 66?

11. Mertsj

No. Let's take some simpler numbers and see if you can understand. What if I have 12 = 2x Could you solve that? And how would you do it?

12. anonymous

6 12 ÷ 2 = 6?

13. Mertsj

Yes. look at what I am going to draw.

14. Mertsj

|dw:1328200164853:dw|

15. Mertsj

So these equations that you have to solve are exactly like that.

16. Mertsj

do you have a calculator?

17. anonymous

Yes

18. Mertsj

Write this down on a piece of paper; 66=P(.03)(2)

19. anonymous

k

20. Mertsj

Now multiply .03 times 2

21. Mertsj

What did you get?

22. anonymous

.06

23. Mertsj

So now write this: 66=P(.06)

24. anonymous

k

25. Mertsj

Now divide both sides of the equation by .06 like I showed you in the drawing.

26. anonymous

p = 1100

27. anonymous

:D ahh i see

28. Mertsj

Very good. Now set up the next one and tell me how you set it up. NOT the answer, just the set-up.

29. anonymous

ok

30. anonymous

72 = P(.04)(2)

31. Mertsj

Perfect!! Now, can you solve it?

32. anonymous

yes :D!

33. Mertsj

Great. Tell me what you get.

34. anonymous

P = 800?

35. Mertsj

That's not what I got. You check your answer and I will check mine.

36. anonymous

well i got 1800 = p but I did not know what to do with the (2) in 72 = P(.04)(2)

37. Mertsj

(.04)(2) means .04 times 2 so multiply them together first.

38. Mertsj

Then you should have 72=P(.08)

39. anonymous

yes

40. Mertsj

Now divide both sides of the equation by .08

41. Mertsj

Like I showed you in the drawing.

42. anonymous

p = 900

43. Mertsj

Bingo!!! Now try the last one.

44. Mertsj

45. anonymous

72 = P(.04)(2) .04 x 2 = .08 72 = P(.08) 1,900 = p that??

46. Mertsj

Well that is all perfect except when you divided both sides by .08 you must have hit a wrong button. So try the division part again.

47. Mertsj

Oh. just a minute. That is the same problem we just did.

48. anonymous

oh you want the next?

49. Mertsj

Yes. The last problem.

50. Mertsj

The final problem in the list.

51. anonymous

seventy-two dollars over 3 years at an interest rate of two percent 72 = P (.02)(3) 72 = P (.06) 1,200 = p

52. Mertsj

WOW!!! You are just too smart!

53. anonymous

:D ty for teaching me!!!

54. Mertsj

yw

55. anonymous

sorry i took so long to understand o.o

56. Mertsj

That's ok. We all have trouble with stuff. It's just not the same stuff for everyone.

57. anonymous

thanks :)

58. Mertsj

yw