Janice deposited $750 in a savings account that earns 3.5% simple interest. How much interest has Janice earned by the end of the first year?

Question

gschibby · Answer

$$750*1,035=?$$

anonymous · Answer

How did you figure this? your right i just would like to get it to. lol

gschibby · Answer

Well, 3,5% is the same as 0,035, but since you already have the deposit, you have to have to 1, too. You could also write it out like this $$Interest = 750*0,035=262,5$$
that would be the correct answer to your question, but the amount on the account would be:$$Amount = savings+interest = 750+(750*0,035)$$
It's just easier to write$$750*1,035$$ directly ;P

anonymous · Answer

How would i do this one? Aaron deposited $591.07 in a savings account that earns 3.7% simple intrest. What is Aaron's account balance after seven years.

gschibby · Answer

Hm, I'm a little sketchy on what "simple interest" means :P

gschibby · Answer

If it means that the interest won't change in seven years it's easy:$$Balance = 591,07*1,037^{7}$$

gschibby · Answer

wich is 762,24 ;)

anonymous · Answer

Susan currently has an account balance of 1336.60. Her initial deposit on the account was $820 and it earned 4.5% simple interest. How long has she held the account?

gschibby · Answer

Since the question is still open, I'll just answer it :P
Set it up like this:
$$1336.60=820*1.045^{x}$$
Then you solve for x:
$$1.048^{x}=\frac{ 1336.6 }{ 820 }=1.63$$
$$\ln 1.045^{x}=\ln1.63$$
That way, when using natural logarisms, you can move the x down:
$$x*\ln 1.045=\ln 1.63$$
$$x=\frac{ \ln 1.63 }{ \ln 1.045 }=11.0998\approx11.1$$
This means that Susan has held the account for 11.1 years :)

gschibby · Answer

Then you can check it:
$$820*1.045^{11.1}=1336.6$$
;)