## 00kirsten Group Title How much money would you have to invest to make $300 within 2 years if the interest rate was 4.5%? 3 years ago 3 years ago • This Question is Closed 1. INewton Group Title $x \times 1.045^2 \geq 300 \implies x \geq \frac{300}{1.045^2}$ 2. 00kirsten Group Title umm so whats the answer?? 3. INewton Group Title Umm, umm, umm... the answer is do your own homework, kiddo. 4. INewton Group Title Or read what I posted and work out the answer for yourself. 5. INewton Group Title Interest rate of 4.5% => value goes up by a factor of 1.045 each year. 6. 00kirsten Group Title but that is confusing, thats not what it shows me to do on my practice stuff 7. 00kirsten Group Title my practice stuff is like P = r x t stuff ... what you posted looks nothing like what im supposed to do, thats why i dont understand what u wrote 8. INewton Group Title If m money is invested, you have 1.045m after one year, and 1.045^2 m money after two years. if this equals 300, you have m = 300/1.045^2 = 287.08 to 2 decimal places. So if you want over 300, the mimnimum amount (to the nearest$) is 288. There.

9. INewton Group Title

Where 1.045^2 = 1.045 x 1.045

10. 00kirsten Group Title

isnt it supposed to look something like ... 300 x .045 x 2 = ??

11. INewton Group Title

Oh, you want 300 extra, not 300 in total? My mistake, sorry. It would be m * 0.045 * 0.045 = 300 m=300/0.045^2 = 300/(0.045 * 0.45)

12. 00kirsten Group Title

300/0.045 x 2 = ?? is that wat its supposed to be like

13. INewton Group Title

The last one was a typo, sorry again. They're both 0.045. But it's 0.045 TIMES ITSELF. Not x 2. Sorry, so many silly mistakes by me, I was a little too mean earlier.

14. INewton Group Title

300/(0.045 x 0.045)

15. 00kirsten Group Title

are you sure lol

16. INewton Group Title

I study Mathematics at the best University in the world. I am sure.

17. 00kirsten Group Title

and what university is that mr.newton

18. INewton Group Title

Cambridge, England.

19. 00kirsten Group Title

ohhh ic. My dads home england. So about that equation ... why did u do 0.045 twice??? im pretty sure i have to show the 2 in my equation

20. INewton Group Title

In the first year, it goes up by 4.5% , so you have 0.045 more. The second year, it goes up by it again, so you have ((1.045) x starting money) x 1.045) = starting money x 1.045 x 1.045 or 1.045^2. The extra money is 0.045 x 0.045 x starting money, and this is equal to 300.

21. INewton Group Title

Wait, one second. Sorry, it's about 4am here. You have 1.045 * 1.045 the starting money. If you want 300 extra, then 1.045^2 x starting money = starting money +300 So 300 = (1.045^2-1)m so m = 300/(1.045^2-1) = 300/((2.045)(0.045)). Wow, I am so sorry. What is wrong with me today. The answer is $3259.98 =$3260 3260 * 1.045 * 1.045 = 3560 = 3260 + 300. WOW, sorry, I have never looked at it for the profit not total, so made a silly mistake. Goodnight, And sorry again. fluttering hell, what's wrong with me today.

22. INewton Group Title

That is possibly the most embarrassingly bad maths I have done in my entire life.

23. 00kirsten Group Title

wat is * ?

24. INewton Group Title

Just another symbol for times, x, I use them interchangeably :(

25. 00kirsten Group Title

so he must invest 3259.98 to make $300 within 2 years if the interest rate was 4.5% ??? 26. INewton Group Title Yes, yes - 300/(1.045 x 1.045 - 1) = 300/(2.045 x 0.45) = 3259.98 3259.9837, to be exact, but$3260 is probably what you want. I am going, sorry for wasting your time (and mine, I am going to have about 3 hours sleep now :/) Have a nice life.

27. 00kirsten Group Title

ok thank you...