Missing something from the equation...WHAT IS IT?

smclean23

After paying a 10 percent tax on all income over $3,000, a person had a net income of $12,000. What was the income before taxes?
(A) $13,300
(B) $13,000
(C) $12,900
(D) $10,000
(E) $9,000

I backsolved and got the answer but I want to use a more structured way of getting the answer.

I tried .10(x-3000)=12000, but it seems like I'm missing something from this equation. What is it?

dbart06 · Posted: Sun Jul 06, 2008 4:24 pm Post subject:

smclean23,

I too got lost in the formula. I discovered that the formula should read:

x-.1(x-3000)=12000

you set up the equation to find the income that was taxed but you have to subtract that number from x.

hope it helps.

smclean23 · Posted: Sun Jul 06, 2008 4:27 pm Post subject:

thanks...makes more sense now...

smclean23 · Posted: Sun Jul 06, 2008 4:33 pm Post subject:

Actually, I tried the formula and it doesnt give me 13,000......Do you?

dbart06 · Posted: Sun Jul 06, 2008 6:18 pm Post subject:

x-.1(x-300)=12000
you have -.1 times x and -.1 times -300, this make 300 a positive # and then you subtract that from both sides..it gives an equation:

x-.1x=11700 => .9x=11700

x=13000

dbart06 · Posted: Sun Jul 06, 2008 6:39 pm Post subject:

x-.1(x-300)=12000
you have -.1 times x and -.1 times -300, this make 300 a positive # and then you subtract that from both sides..it gives an equation:

x-.1x=11700 => .9x=11700

x=13000

beeparoo · Posted: Wed Jul 09, 2008 10:17 am Post subject:

dbart06 · Posted: Wed Jul 09, 2008 10:35 am Post subject:

sorry for the typo should be:

x-.1(x-3000)=12000

thanks beeparoo. these are the mistakes that cost me on the test.

dbart06 · Posted: Wed Jul 09, 2008 10:45 am Post subject:

sorry for the typo should be:

x-.1(x-3000)=12000

thanks beeparoo. these are the mistakes that cost me on the test.

lion147 · Posted: Wed Jul 09, 2008 5:46 pm Post subject:

I think an easier equation is:

3000+0.9x = 12000

Where x is the taxable income, the answer is 3000+x.

i.e. 0.9x = 9000, x = 9000/0.9, x = 10000, answer is 10000+3000.

senthil · Posted: Wed Jul 09, 2008 6:03 pm Post subject:

I tried the same way as lioner has done , that is the easiest approach too