SOLUTION: Please help me solve this equation. Thank you. Deducting Sales Tax... A tax -exmpt charity recieved a bill of $145.90 for a sump pump. The bill incorrectly included sales tax of

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: Please help me solve this equation. Thank you. Deducting Sales Tax... A tax -exmpt charity recieved a bill of $145.90 for a sump pump. The bill incorrectly included sales tax of      Log On


   



Question 635823: Please help me solve this equation. Thank you.
Deducting Sales Tax... A tax -exmpt charity recieved a bill of $145.90 for a sump pump. The bill incorrectly included sales tax of 5%. How much does the charity owe?

I know the correct way to think of the problem is... The origional price, a variable, + 5% of the origional price equals $ 145.90. I've came up with this so far...

5% is converted to 0.05
0.05 * 145.90 = 7.295
145.90 - 0.05 = 145.85
so would the answer be $ 145.85 ????

Answer by KMST(5328) About Me  (Show Source):
You can put this solution on YOUR website!
No, that's not right. Here is why.
The calculation
0.05 * 145.90 = 7.295
gives you 5% of 145.90.
That is 5% of the total bill, which included tax.
However, the sales tax was 5% of the unknown amount that you have to find (the price of the sump pump).
Let the price of the sump pump be $x .
The tax would be $0.05%2Ax
For a customer that must pay sales tax, the bill (in $) would be
x%2B0.05x=%281%2B0.05%29x=1.05x
That is 105% of the price, 100% of the price for the merchant, and $5% of the price (the sales tax) for the government.
That is how the merchant calculated (incorrectly) the bill for the tax-exempt charity.
1.05x=145.90
We must solve that equation for x .
Dividing both sides of the equal sign by 1.05 we get
1.05x=145.90 --> 1.05x%2F1.05=145.90%2F1.05 --> highlight%28x=138.95%29 (rounding)
The price of the pump was $138.95, and that is all that the charity should pay.
The 5% tax on $138.95 calculates as
0.05*($138.95)=$6.9475, which rounds to $6.95.
The merchant added $138.95+$6.95=$145.90 to come up with the incorrect bill.