Difference between revisions of "1986 AHSME Problems/Problem 20"
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− | We see that <math>x</math> is multiplied by <math>\frac{100+p}{100}</math> when it is increased by <math>p | + | We see that <math>x</math> is multiplied by <math>\frac{100+p}{100}</math> when it is increased by <math>p</math>%. Therefore, <math>y</math> is multiplied by <math>\frac{100}{100+p}</math>, and so it is decreased by <math>\frac{p}{100+p}</math> times itself. Therefore, it is decreased by <math>\frac{100p}{100+p}</math>%, and so the answer is <math>\boxed{E}</math>. |
== See also == | == See also == |
Latest revision as of 18:50, 9 October 2017
Problem
Suppose and are inversely proportional and positive. If increases by , then decreases by
Solution
We see that is multiplied by when it is increased by %. Therefore, is multiplied by , and so it is decreased by times itself. Therefore, it is decreased by %, and so the answer is .
See also
1986 AHSME (Problems • Answer Key • Resources) | ||
Preceded by Problem 19 |
Followed by Problem 21 | |
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All AHSME Problems and Solutions |
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