Difference between revisions of "1998 AJHSME Problems/Problem 9"

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==Problem 9==
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==Problem==
  
 
For a sale, a store owner reduces the price of a <dollar/><math>10</math> scarf by <math>20\% </math>.  Later the price is lowered again, this time by one-half the reduced price.  The price is now
 
For a sale, a store owner reduces the price of a <dollar/><math>10</math> scarf by <math>20\% </math>.  Later the price is lowered again, this time by one-half the reduced price.  The price is now
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<math>\text{(A)}\ 2.00\text{ dollars} \qquad \text{(B)}\ 3.75\text{ dollars} \qquad \text{(C)}\ 4.00\text{ dollars} \qquad \text{(D)}\ 4.90\text{ dollars} \qquad \text{(E)}\ 6.40\text{ dollars}</math>
 
<math>\text{(A)}\ 2.00\text{ dollars} \qquad \text{(B)}\ 3.75\text{ dollars} \qquad \text{(C)}\ 4.00\text{ dollars} \qquad \text{(D)}\ 4.90\text{ dollars} \qquad \text{(E)}\ 6.40\text{ dollars}</math>
  
==Solution 1==
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==Solution==
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===Solution 1===
  
 
<math>100\%-20\%=80\%</math>
 
<math>100\%-20\%=80\%</math>
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<math>\frac{8}{2}=4=\boxed{C}</math>
 
<math>\frac{8}{2}=4=\boxed{C}</math>
  
==Solution 2==
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===Solution 2===
  
 
The first discount has percentage 20, which is then discounted again for half of the already discounted price.
 
The first discount has percentage 20, which is then discounted again for half of the already discounted price.

Revision as of 11:49, 23 December 2012

Problem

For a sale, a store owner reduces the price of a <dollar/>$10$ scarf by $20\%$. Later the price is lowered again, this time by one-half the reduced price. The price is now

$\text{(A)}\ 2.00\text{ dollars} \qquad \text{(B)}\ 3.75\text{ dollars} \qquad \text{(C)}\ 4.00\text{ dollars} \qquad \text{(D)}\ 4.90\text{ dollars} \qquad \text{(E)}\ 6.40\text{ dollars}$

Solution

Solution 1

$100\%-20\%=80\%$

$10\times80\%=10\times0.8$

$10\times0.8=8$

$\frac{8}{2}=4=\boxed{C}$

Solution 2

The first discount has percentage 20, which is then discounted again for half of the already discounted price.

$100-20=80$

$\frac{80}{2}=40$

$40\%\times10=10\times0.4=4=\boxed{C}$

See also

1998 AJHSME (ProblemsAnswer KeyResources)
Preceded by
Problem 8
Followed by
Problem 10
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
All AJHSME/AMC 8 Problems and Solutions