document.write( "Question 1209197: Megan wants to buy an item worth $400. She has two coupons of 10% and 15% off. What is the total discount rate, as a percentage, if she used both coupons? Hint: The answer is not 25% \n" ); document.write( "

Algebra.Com's Answer #847811 by ikleyn(52787) $\"\"$ $\"About$

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document.write( "First coupon reduces the buying price from $400 to  (1-0.1)*400 = 0.9*400 = 360 dollars.\r\n" );
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document.write( "Second coupon reduces the buying price from $360 to  (1-0.15)*360 = 0.85*360 = 306 dollars.\r\n" );
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document.write( "The total discount rate of the two coupons is   = 0.235.\r\n" );
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document.write( "Notice the remarkable fact that this value of 0.235 coincides with\r\n" );
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document.write( "    1 - (1-0.1)*(1-0.75) = 1 - 0.9*0.85 = 0.235.\r\n" );
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document.write( "It explain you an idea on HOW TO calculate an effective discount rate for a chain of discounts.\r\n" );
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