2001 AMC 10 Problems/Problem 7
Contents
Problem
When the decimal point of a certain positive decimal number is moved four places to the right, the new number is four times the reciprocal of the original number. What is the original number?
Solution 1
If is the number, then moving the decimal point four places to the right is the same as multiplying by . This gives us the equation This is equivalent to Since is positive, it follows that
Solution 2
Alternatively, we could try each solution and see if it fits the problems given statements.
After testing, we find that is the correct answer.
~ljlbox
See Also
2001 AMC 10 (Problems • Answer Key • Resources) | ||
Preceded by Problem 6 |
Followed by Problem 8 | |
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All AMC 10 Problems and Solutions |
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