1. ## interest problem

hello everyone. i hope this isn't too stupid a question or i didn't post it in the wrong section, i believe this is the right one based on the description.

anyway, i am studying for a placement test and my math skills are pretty atrocious. on a study guide i am using i have come across an interest problem and i can't figure out how exactly to solve it.

it's a word problem:
Enrique put his money in the credit union for one year. His money earned 8% simple interest and at the end of the year his account was worth $1350. How much was originally invested? now here is where i will look truly pathetic. in the answer section of the study guide it gives me not only the answer to the problem but the equation used to solve it:$1250; x + 0. 08x = 1350

the thing is, when i look at the equation x + .08x = 1350, i can't figure out how to solve it. i think it is the decimal that is throwing me off. i would appreciate if someone could break down exactly how to work a problem like this out on paper without using a calculator.

2. ## Re: interest problem

Originally Posted by rainbowserpent
hello everyone. i hope this isn't too stupid a question or i didn't post it in the wrong section, i believe this is the right one based on the description.

anyway, i am studying for a placement test and my math skills are pretty atrocious. on a study guide i am using i have come across an interest problem and i can't figure out how exactly to solve it.

it's a word problem:
Enrique put his money in the credit union for one year. His money earned 8% simple interest and at the end of the year his account was worth $1350. How much was originally invested? now here is where i will look truly pathetic. in the answer section of the study guide it gives me not only the answer to the problem but the equation used to solve it:$1250; x + 0. 08x = 1350

the thing is, when i look at the equation x + .08x = 1350, i can't figure out how to solve it. i think it is the decimal that is throwing me off. i would appreciate if someone could break down exactly how to work a problem like this out on paper without using a calculator.
Add the two terms on the left hand side. Then the next line is:

1.08x = 1350 ....

I would hope you know what to do next.

3. ## Re: interest problem

Originally Posted by rainbowserpent
x + 0. 08x = 1350
That means 1x + .08x; like 1 apple plus .08 apple = 1.08 apples.
Remember that any variable by itself has an implied "1"; like v = 1v.

4. ## Re: interest problem

If your math skills are "atrocious" why are you trying so hard to pass a placement test at a higher level and avoid a class that would help you improve your class skills. You should want a score that accurately assses your ability, not one that is based on last minute prepping for specific questions.

5. ## Re: interest problem

Formula: $Prt=I$
Principal * rate * time = Investment

6. ## Re: interest problem

Originally Posted by theloser
Formula: $Prt=I$
Principal * rate * time = Investment
= Interest (not Investment)