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POFind a random integer which creates another integer, when using percentages
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copied!<p><strong>Solved, for the precise solution for my problem, see my answer</strong></p> <p>I am sorry about the confusing title, let me clarify my problem:</p> <p>My Java program is supposed to ask a math question with percentages.</p> <p>It should create a question in this format:</p> <pre><code>25% of 4616 = ? </code></pre> <p>The requirements are:</p> <ul> <li>the percentage is always dividable by 5 (no problem)</li> <li>the number (here 4616) has to be between 100 and 9999 (also not a problem)</li> <li>the number as well as the result has to be an integer (this is my problem)</li> </ul> <p>Is there any fast method to find a random number which fulfills the last requirement?</p> <p>The only solution I can think of is to find the percentage, then create a loop which will not stop until a random number is found which fulfills the requirement (in the example until <code>number % 4 == 0</code> is true)</p> <p>But this loop could run thousands of times until a correct number is found.</p> <p>Is there a better method for my problem?</p> <p><strong>Edit:</strong> It seems that I didn't make clear what my problem is, I don't want double numbers as a result, only integer.</p> <p>E.g.: If my percentage is 65%, then a possible question would be </p> <blockquote> <p>65% of 7620 = ?</p> </blockquote> <p>because the solution 4953 is also a whole number.</p> <p>I want to find a random number between 100 and 9999 which is a whole number AND has a whole number as a result to the equation p * x = y.</p>

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