53 lines
1.2 KiB
Markdown
53 lines
1.2 KiB
Markdown
---
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id: 5900f3b61000cf542c50fec8
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title: 'Problem 73: Counting fractions in a range'
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challengeType: 5
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forumTopicId: 302186
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dashedName: problem-73-counting-fractions-in-a-range
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---
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# --description--
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Consider the fraction, `n`/`d`, where n and d are positive integers. If `n`<`d` and HCF(`n`,`d`)=1, it is called a reduced proper fraction.
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If we list the set of reduced proper fractions for `d` ≤ 8 in ascending order of size, we get:
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<div style='text-align: center;'>1/8, 1/7, 1/6, 1/5, 1/4, 2/7, 1/3, <strong>3/8</strong>, <strong>2/5</strong>, <strong>3/7</strong>, 1/2, 4/7, 3/5, 5/8, 2/3, 5/7, 3/4, 4/5, 5/6, 6/7, 7/8</div>
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It can be seen that there are 3 fractions between 1/3 and 1/2.
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How many fractions lie between 1/3 and 1/2 in the sorted set of reduced proper fractions for `d` ≤ 12,000?
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# --hints--
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`countingFractionsInARange()` should return a number.
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```js
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assert(typeof countingFractionsInARange() === 'number');
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```
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`countingFractionsInARange()` should return 7295372.
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```js
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assert.strictEqual(countingFractionsInARange(), 7295372);
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```
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# --seed--
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## --seed-contents--
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```js
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function countingFractionsInARange() {
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return true;
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}
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countingFractionsInARange();
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```
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# --solutions--
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```js
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// solution required
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```
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