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If you are unsure of how to do a question, click on Reveal answers to see the full working. Then, once you understand how to do the question, click on Try another question like this one to start again. Do each question repeatedly to ensure you have mastered it.

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Suppose {company} purchased a $\\var{full}$-day promissory note at a yield of $\\var{originalipa}\\%$ per annum. The promissory note had a face value of $\\$\\var{S}$. After holding the promissory note for $\\var{soldafter}$ days {company} sold the promissory note at a yield of $\\var{nextipa}\\%$ per annum.

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a)

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We are asked to find the present value of a promissory note. We do this using simple interest. Therefore we will use the equation

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$\\displaystyle P=\\frac{S}{(1+rt)}$,

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where $P$ is the present value, $S$ is the future value (the face value, or the value at maturity), $r$ is the interest rate (or the yield) per annum and $t$ is the time in years.

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In our situation we have,

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$S=\\var{S}$,

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$r=\\var{originalipa}\\%=\\var{originalipadec}$,

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$t=\\frac{\\var{full}}{365}$, 

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and therefore

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$\\begin{align}P&=\\frac{\\var{S}}{1+\\var{originalipadec}\\times \\frac{\\var{full}}{365}}\\\\&=\\$ \\var{aProunded} \\text{        (to the nearest cent)}\\end{align}$ 

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b)

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We are asked to find the present value of a promissory note. We do this using simple interest. Therefore we will use the equation

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$\\displaystyle P=\\frac{S}{(1+rt)}$,

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where $P$ is the present value, $S$ is the future value (the face value, or the value at maturity), $r$ is the interest rate (or the yield) per annum and $t$ is the time in years.

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In our situation we have,

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$S=\\var{S}$,

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$r=\\var{nextipa}\\%=\\var{nextipadec}$,

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$t=\\frac{\\var{left}}{365}$, (since $\\var{full}-\\var{soldafter}=\\var{left}$)

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and therefore

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$\\begin{align}P&=\\frac{\\var{S}}{1+\\var{nextipadec}\\times \\frac{\\var{left}}{365}}\\\\&=\\$ \\var{bProunded} \\text{        (to the nearest cent)}\\end{align}$ 

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c)

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Since {company} purchased the promissory note for $\\$\\var{aProunded}$ and sold it for $\\$\\var{bProunded}$ the dollar return was $\\$\\var{bProunded}-\\$\\var{aProunded}=\\$\\var{c}$

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d)

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We are asked to find the interest rate using simple interest. Therefore we could use the equation

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$I=Ptr$,

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where $I$ is the interest amount, $P$ is the present value, $t$ is the time in years and $r$ is the interest rate per annum.

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In our situation we have,

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$I=\\var{c}$,

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$P=\\var{aProunded}$,

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$t=\\frac{\\var{soldafter}}{365}$, 

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and therefore we have

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$\\displaystyle \\var{c}=\\var{aProunded}\\times \\frac{\\var{soldafter}}{365}\\times r$

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which we need to rearrange to solve for $r$.

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We want to get $r$ by itself. We can do this by dividing both sides by $\\var{aProunded}\\times \\frac{\\var{soldafter}}{365}$ (in order to remove the multiplication by $\\var{aProunded}\\times \\frac{\\var{soldafter}}{365}$)

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$\\displaystyle \\frac{\\var{c}}{\\var{aProunded}\\times \\frac{\\var{soldafter}}{365}}=r$

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Calculating this we find 

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$\\begin{align}r&\\approx\\var{ddec}\\\\&=\\var{drounded}\\%\\text{        (to 2 decimal places)}\\end{align}$

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present value

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I=Ptr -> c=aP*soldafter/365*r

", "group": "Ungrouped variables", "definition": "365*c/(aP*soldafter)"}, "originalipa": {"templateType": "anything", "name": "originalipa", "description": "

interest per annum as a percentage (add the symbol afterwards)

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Calculate the purchase priced that {company} paid
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$\\$\\,$[[0]] (to the nearest cent)
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Calculate the sale price that {company} received
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$\\$$ [[0]] (to the nearest cent)
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Calculate the dollar returned earned by {company} for this period of holding the promissory note.
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$\\$$ [[0]] (to the nearest cent)
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", "gaps": [{"allowFractions": false, "unitTests": [], "useCustomName": false, "minValue": "c", "extendBaseMarkingAlgorithm": true, "showFeedbackIcon": true, "precisionType": "dp", "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain", "precision": "2", "mustBeReducedPC": 0, "mustBeReduced": false, "customMarkingAlgorithm": "", "variableReplacementStrategy": "originalfirst", "correctAnswerFraction": false, "customName": "", "scripts": {}, "precisionMessage": "You have not given your answer to the nearest cent.", "variableReplacements": [], "showCorrectAnswer": true, "type": "numberentry", "precisionPartialCredit": 0, "strictPrecision": false, "maxValue": "c", "showPrecisionHint": false, "marks": 1}], "customMarkingAlgorithm": "", "variableReplacementStrategy": "originalfirst", "sortAnswers": false, "marks": 0, "unitTests": []}, {"customName": "", "scripts": {}, "useCustomName": false, "variableReplacements": [], "showCorrectAnswer": true, "type": "gapfill", "extendBaseMarkingAlgorithm": true, "showFeedbackIcon": true, "prompt": "
Calculate the simple interest rate per annum earned by {company} from the promissory note.
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[[0]]$\\%$ p.a. (to two decimal places)
", "gaps": [{"allowFractions": false, "unitTests": [], "useCustomName": false, "minValue": "d", "extendBaseMarkingAlgorithm": true, "showFeedbackIcon": true, "precisionType": "dp", "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain", "precision": "2", "mustBeReducedPC": 0, "mustBeReduced": false, "customMarkingAlgorithm": "", "variableReplacementStrategy": "originalfirst", "correctAnswerFraction": false, "customName": "", "scripts": {}, "precisionMessage": "You have not given your answer to two decimal places.", "variableReplacements": [], "showCorrectAnswer": true, "type": "numberentry", "precisionPartialCredit": 0, "strictPrecision": false, "maxValue": "d", "showPrecisionHint": false, "marks": 1}], "customMarkingAlgorithm": "", "variableReplacementStrategy": "originalfirst", "sortAnswers": false, "marks": 0, "unitTests": []}], "contributors": [{"name": "Ben Brawn", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/605/"}]}]}], "contributors": [{"name": "Ben Brawn", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/605/"}]}