SOLUTION: An instrument store gives a 10% discount to all students off the original cost of an instrument. During a back to school sale an additional 15% is taken off the discounted price. J

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Question 127579: An instrument store gives a 10% discount to all students off the original cost of an instrument. During a back to school sale an additional 15% is taken off the discounted price. Julie, a student at the local high school, purchases a flute for $306. How much did it originally cost?

I really need some help on this one.
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!
The original price was x. So after the 10% discount the price was 0.9x. That price was then discounted 15%, so the price is now %280.85%29%28.9%29x, but we know this expression is equal to $306, because that is what was paid. So:

%280.85%29%28.9%29x=306

0.765x=306

x=306%2F.765

x=400

Check:
If the original price was 400, the 10% discount price would have been 400 - 40 = 360, then the 15% discount would have been 360 * .15 = 54, so the final price would be 360 - 54 = 306. Checks.