INTEREST HELP!!!: Jacques invests a total of $10,000 in two mutual funds. After 1 yr, one fund produced 12% growth, and the other lost 3%. Find the amount invested in each fund if the total investment grew by $900.

Question

fanduekisses · Answer

prt + prt = 900 ????

anonymous · Answer

Theoretically, yes, but we don't know either p.

anonymous · Answer

You need a second equation. Any ideas?

fanduekisses · Answer

mhmmm P = I/rt ???

fanduekisses · Answer

:((

wolf1728 · Answer

prin1 * 1.12 = total 1
prin2 * 1.03 = total 2

prin1 * 1.12 + prin2 * 1.03 = 10,900.00

fanduekisses · Answer

why 1.12 and 1.03????

wolf1728 · Answer

that's 12% and 3% interest

anonymous · Answer

Actually it's 1.12 for the 12% growth and 0.97 for the 3% loss. So if we say P1 goes with 12% and P2 goes with -3% then we have

$$1.12P _{1}+0.97P _{2} = 10900$$

anonymous · Answer

But you still need a second equation. Both principles add up to 10000, so
$$P _{1}+P _{2}=10000$$

wolf1728 · Answer

Sorry for forgetting the signs :-(

anonymous · Answer

And you need to solve that system of equations

fanduekisses · Answer

why 1.12 and not 0.12? I'm so confused right now sorry if it sounds dumb.

wolf1728 · Answer

I'm happy to help you but it seems openstudy keeps bouncing me out of here

anonymous · Answer

@wolf1728 I'm having that problem as well

anonymous · Answer

You can do use either and still get the same answer. If you use 1.12 and 0.97, then the taking into account the money already in the account. That's why it adds up to 10900. If you only use 0.12 and -0.03, then you're only accounting for the interest. In that case the equation will be
$$0.12P _{1}-0.03P _{2}=900$$

fanduekisses · Answer

oooooooooh I'm starting to understand it now. ok I'll try solving the system of equations now. :D Thanks.

wolf1728 · Answer

Yeah openstudy ARRGGGHHHH!!!!!!
Anyway if we wanted to see how mush 12% interest yields on 10,000 for one year the formula is :
principal*(1 + rate )^years
10,000 * 1.12^1 = 11,200

fanduekisses · Answer

Ohh thank you, so helpful!

wolf1728 · Answer

Yeah, I had a feeling you'd want that 1.12 explained a little bit better. Here's a good page that explains compound interest: http://www.1728.org/compint2.htm

fanduekisses · Answer

Thank you ^_^