// Numbas version: exam_results_page_options {"name": "Simon's copy of Geometric progression: The nth term of a series", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"metadata": {"description": "

Find the nth term of a Geometric progression

", "licence": "Creative Commons Attribution-NonCommercial 4.0 International"}, "preamble": {"css": "", "js": ""}, "advice": "

If the ratio between successive pairs of terms is a constant then the series under examination is a geometric progression.

\n

Ths first term is \\(a\\) and the common ratio is \\(r\\).

\n

The formula for the nth term of the series is given by:    \\(T_n=ar^{n-1}\\)

\n

In this example \\(a=\\var{a}\\),   \\(r = \\frac{\\simplify{{a}*{r}}}{\\var{a}}=\\var{r}\\)  and  \\(n = \\var{n}\\)

\n

\\(T_\\var{n}=\\var{a}\\times\\var{r}^{\\var{n}-1}\\)

\n

\\(T_\\var{n}=\\var{a}\\times\\simplify{{r}^{{n}-1}}\\)

\n

\\(T_\\var{n}=\\simplify{{a}*{r}^{{n}-1}}\\)

", "tags": [], "functions": {}, "parts": [{"sortAnswers": false, "marks": 0, "variableReplacements": [], "unitTests": [], "extendBaseMarkingAlgorithm": true, "showCorrectAnswer": true, "gaps": [{"precisionType": "dp", "unitTests": [], "correctAnswerFraction": false, "type": "numberentry", "customMarkingAlgorithm": "", "showFeedbackIcon": true, "scripts": {}, "minValue": "{a}*r^({n}-1)", "notationStyles": ["plain", "en", "si-en"], "marks": 1, "precisionPartialCredit": 0, "correctAnswerStyle": "plain", "mustBeReduced": false, "variableReplacements": [], "extendBaseMarkingAlgorithm": true, "showCorrectAnswer": true, "allowFractions": false, "variableReplacementStrategy": "originalfirst", "precision": "3", "showPrecisionHint": true, "strictPrecision": false, "maxValue": "{a}*r^({n}-1)", "mustBeReducedPC": 0, "precisionMessage": "You have not given your answer to the correct precision."}], "type": "gapfill", "prompt": "

Calculate the \\(\\var{n}th\\) term of the series.

\n

\\(T_\\var{n}=\\) [[0]]

", "showFeedbackIcon": true, "customMarkingAlgorithm": "", "scripts": {}, "variableReplacementStrategy": "originalfirst"}], "rulesets": {}, "ungrouped_variables": ["a", "r", "n"], "extensions": [], "variablesTest": {"maxRuns": 100, "condition": "r<>1"}, "variables": {"a": {"templateType": "randrange", "description": "", "group": "Ungrouped variables", "definition": "random(1..12#1)", "name": "a"}, "r": {"templateType": "randrange", "description": "", "group": "Ungrouped variables", "definition": "random(0.4..3#0.2)", "name": "r"}, "n": {"templateType": "randrange", "description": "", "group": "Ungrouped variables", "definition": "random(4..9#1)", "name": "n"}}, "name": "Simon's copy of Geometric progression: The nth term of a series", "variable_groups": [], "statement": "

The first three terms of a geometric progression are given by:  

\n

\\(\\var{a} + \\simplify{{a}*{r}} + \\simplify{{a}*{r}^2}\\,+ \\, ...........\\)

", "type": "question", "contributors": [{"name": "Frank Doheny", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/789/"}, {"name": "Simon Thomas", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/3148/"}]}]}], "contributors": [{"name": "Frank Doheny", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/789/"}, {"name": "Simon Thomas", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/3148/"}]}