// Numbas version: exam_results_page_options {"name": "Fractions: Lowest form", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"variable_groups": [], "variables": {"d": {"templateType": "anything", "group": "Ungrouped variables", "definition": "map(c[x]*a[x],x,0..3)", "name": "d", "description": ""}, "a": {"templateType": "anything", "group": "Ungrouped variables", "definition": "[random(-9..-5),random(5..9),random(11..19),random(35..61)]", "name": "a", "description": ""}, "b": {"templateType": "anything", "group": "Ungrouped variables", "definition": "map(chcp(a[x],2,9,random(2..9)),x,0..2)+chcp(a[3],40,80,random(40..80))", "name": "b", "description": ""}, "c": {"templateType": "anything", "group": "Ungrouped variables", "definition": "[random(2..9),random(2..9),random(2..9),random(40..70)]", "name": "c", "description": ""}, "f": {"templateType": "anything", "group": "Ungrouped variables", "definition": "map(c[x]*b[x],x,0..3)", "name": "f", "description": ""}}, "ungrouped_variables": ["a", "c", "b", "d", "f"], "question_groups": [{"pickingStrategy": "all-ordered", "questions": [], "name": "", "pickQuestions": 0}], "name": "Fractions: Lowest form", "functions": {"chcp": {"type": "number", "language": "jme", "definition": "if(gcd(a,d)=1,d,chcp(a,b,c,random(b..c)))", "parameters": [["a", "number"], ["b", "number"], ["c", "number"], ["d", "number"]]}}, "showQuestionGroupNames": false, "parts": [{"marks": 0, "scripts": {}, "gaps": [{"answer": "{a[0]}/{b[0]}", "musthave": {"message": "

Input as a fraction.

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Input as a fraction in lowest form without brackets.

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Input as a fraction in lowest form by cancelling common factors in the denominator and numerator.

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Input as a fraction.

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Input as a fraction in lowest form without brackets.

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Input as a fraction in lowest form by cancelling common factors in the denominator and numerator.

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Input as a fraction.

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Input as a fraction in lowest form. Do not include brackets in your answer.

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Input as a fraction in lowest form by cancelling common factors in the denominator and numerator.

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Input as a fraction.

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Input as a fraction in lowest form. Do not include brackets in your answer.

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Input as a fraction in lowest form by cancelling common factors in the denominator and numerator.

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Given a fraction $\\displaystyle \\frac{a}{b}$ then it is in lowest form if $a$ and $b$ have no common factors. 

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If $c$ was a common factor then we could cancel the $c$ and we have converted the fraction into a fraction with smaller numbers.

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For example the fraction $\\displaystyle \\frac{18}{24}=\\frac{9 \\times 2}{12 \\times 2} = \\frac{9}{12}$ as we can cancel the common factor $2$.

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But we are not yet finished as $\\displaystyle \\frac{9}{12}=\\frac{3 \\times 3}{4 \\times 3} = \\frac{3}{4}$ on cancelling the common factor $3$. We cannot go any further as $3$ and $4$ have no common factors (other than $1$, which is never considered as a factor).

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Of  course we could have spotted that $6$ was a common factor  as $\\displaystyle \\frac{18}{24}=\\frac{3 \\times 6}{4 \\times 6}=\\frac{3}{4}$ , but it is perfectly OK to do it in stages as we did above. Just make sure that your final fraction does not have common factors.

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$\\displaystyle \\simplify[noc]{{d[0]}/{f[0]}}\\;=$[[0]],$\\;\\;\\displaystyle \\simplify[noc]{{d[1]}/{f[1]}}\\;=$[[1]],$\\;\\;\\displaystyle \\simplify[noc]{{d[2]}/{f[2]}}\\;=$[[2]],$\\;\\;\\displaystyle \\simplify[noc]{{d[3]}/{f[3]}}\\;=$[[3]]

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Input as fractions and do not include brackets in your answer.

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You can click on Show steps for help. You will not lose any marks if you do.

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Reduce the following fractions to their lowest form.

", "tags": ["Fractions", "SFY0001", "cancellation", "cancelling", "cancelling ", "checked2015", "common factor", "denominator", "lowest form", "numerator"], "rulesets": {"noc": ["std", "!simplifyFractions"], "std": ["all", "fractionNumbers"]}, "preamble": {"css": "", "js": ""}, "type": "question", "metadata": {"notes": "

11/08/2012:

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Added tags.

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Added description.

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Function chcp(a,b,c,d) gives number coprime to a in the range b..c, d is usually random(b..c) for redundant reasons!

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Note that the answer is constrained by max length as well as requiring / and no brackets.

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Reducing fractions to their lowest form by cancelling common factors in the numerator and denominator. There are 4 questions. 

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We have:

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$\\displaystyle \\simplify[noc]{{d[0]}/{f[0]}}=\\simplify[]{({a[0]}*{c[0]})/({b[0]}*{c[0]})}=\\simplify[all]{{a[0]}/{b[0]}}$. Common factor $\\var{c[0]}$.

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$\\displaystyle \\simplify[noc]{{d[1]}/{f[1]}}=\\simplify[]{({a[1]}*{c[1]})/({b[1]}*{c[1]})}=\\simplify[all]{{a[1]}/{b[1]}}$. Common factor $\\var{c[1]}$.

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$\\displaystyle \\simplify[noc]{{d[2]}/{f[2]}}=\\simplify[]{({a[2]}*{c[2]})/({b[2]}*{c[2]})}=\\simplify[all]{{a[2]}/{b[2]}}$. Common factor $\\var{c[2]}$.

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$\\displaystyle \\simplify[noc]{{d[3]}/{f[3]}}=\\simplify[]{({a[3]}*{c[3]})/({b[3]}*{c[3]})}=\\simplify[all]{{a[3]}/{b[3]}}$. Common factor $\\var{c[3]}$.

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