After 15% sale & 7% tax, your bill for a suit is $75. What was the retail price?
i completely forgot how to solve problems like this, but for some reason i have the urge to do 15%-7%= 8% which is probably wrong.
anyways, can someone explain to me how to solve this?
thanks
2007-10-09 12:45:32 · 4 answers · asked by ♥ 2 in Science & Mathematics ➔ Mathematics
i still dont get it and now im annoyed :/
2007-10-09 13:05:39 · update #1
Original price = n
To figure a 15% discount, you multiply by 1 - 0.15 = 0.85
Discounted price = 0.85n
To figure a 7% increase, you multiply by 1 + 0.07 = 1.07
Added tax = 0.85n * 1.07
Final value = 1.07 * 0.85 * n = 75
Now just reverse everything to solve for n:
n = 75 / 0.85 / 1.07
n = 82.46
You can also start by solving this backwards:
You ended with a price of $75.
The discounted price would be d, but with tax would be:
d + 0.07d = 1.07d
1.07d = $75
d = $70.09
This discounted price is 85% of the original price.
0.85n = $70.09
n = $70.09 / 0.85
n = $82.46
Either way you get to the same answer.
2007-10-09 12:54:57 · answer #1 · answered by Puzzling 7 · 0⤊ 0⤋
Don't let the math get to you. Think about how this would happen in real life. You go to a store that has a 15% sale. You look at a coat that has a retail price of $100. How much is the sale price? They take off 15%, right? So they reduce the price by 15% of $100, or $15, and the sale price is $85. (This is the same as saying that an item in a 15% sale has a sale price that is (100 - 15)%, or 85%, of the retail price.)
So you take the coat to the counter. If the sales tax rate is 7%, how much tax do you pay? 7% of that $85, right? So your final bill is $85 + $5.95 = $90.95. This is 85% of the retail price, plus 7% of 85% of the retail price -- that is to say, 0.85 times the retail price, plus 0.07 times 0.85 times the retail price.
Now to your problem. Let P be the retail price. Then the sale price is 0.85P and the tax on that is (0.07)(0.85P). The total of those two is $75.
2007-10-09 20:09:13 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Assume that the retail price is x.
with a 15 % sale, 15 % of x is x(15/100)=15x/100=3x/20. so x-3x/20 is the price.=17x/20
Now a 7% tax. multiply (17x/20) by 7/100.
=119x/2000=75
119x=75(2000)
119x=150000
x=150000/119=$1,260.50
Check your answer and see if you come up with close to $75.
2007-10-09 20:16:10 · answer #3 · answered by cidyah 7 · 0⤊ 0⤋
You do $75.00*15% = 11.25+75= 86.25*7%=6.04 = $92.29
That is your total... I think
2007-10-09 19:55:49 · answer #4 · answered by Jbaby 2 · 0⤊ 0⤋