1. ## percentages

okay--this is easy--but i keep getting a different answer than what the teacher has given--what am i doing wrong?

12 is one half percent of what number--

he said it's 2400--

2. Originally Posted by in2wishin
okay--this is easy--but i keep getting a different answer than what the teacher has given--what am i doing wrong?

12 is one half percent of what number--

he said it's 2400--
your teacher is correct, who would have thunk it, right?

recall that "percentage" means "out of 100" or "divided by 100." so saying 1/2 percent is the same as saying $\frac {\frac {1}{2}}{100} = \frac {1}{200}$

also, in math, "of" means "multiply." so saying "1/2 percent of" means " $\frac {1}{200} \times$"

So let the number be $x$

since 12 is 1/2 percent of $x$, we have:

$12 = \frac {1}{200}x$

$\Rightarrow x = 200(12) = 2400$

3. Originally Posted by in2wishin
okay--this is easy--but i keep getting a different answer than what the teacher has given--what am i doing wrong?

12 is one half percent of what number--

he said it's 2400--

I would think of it like this.

12 = 1/2%
24 = 1%

Now you have an easier number to work with.

1% x 100 = 100%
24 x 100 = 2400

I just work it out like that, though it may prove time consuming with more difficult questions. Just do the same to the left had side as to the right. I know your question has already been answered, but I tried to explain it in a different way.