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The compound interest formula is: $\\ A = P(1+i)^n $

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Part (a)

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n represents the number of compounding periods , so for Bank A it is $\\var{n1}$ years.

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i represents the rate of compound interest, for Bank A, the annual interest rate is $\\var{perc1}$% so i is $\\frac {\\var{perc1}} {100}=\\var{int1}$.

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The total amount saved after $\\var{n1}$ years is denoted by A. Using the compound interest formula:

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$A=P(1+i)^n$

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$A=\\var{P} \\times(1+\\var{int1})^\\var{n1}=\\var{A1}$

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Part(b)

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n represents the number of compounding periods. For Bank B, interest is compounded daily for $\\var{n1}$ years so there are a total of $365 \\times \\var{n1} =\\var{n2}$ compounding periods.

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i represents the rate of compound interest. For Bank B, the interest rate is ${\\var{perc2}}$% per annum compounded daily.

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The interest rate per day is $\\frac{\\var{perc2}}{365}=\\var{int3}$%

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Therefore $i=\\frac{\\var{int3}}{100}=\\var{int2}$

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The amount saved after $\\var{n1}$ years is denoted by A. Using the compound interest formula:

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$A=P(1+i)^n$

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$A=\\var{P} \\times(1+\\var{int2})^\\var{n2}=\\var{A2}$

", "rulesets": {}, "parts": [{"prompt": "

Suppose that the potential customer chooses Bank A.

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What is the value of $n$?

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[[0]]

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What is the value of $i$?

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[[1]]

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What is the value of $A$?  Please give your answer to the nearest cent.

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€[[2]]

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Suppose that the potential customer chooses Bank B.

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What is the value of $n$?  

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[[0]]

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What is the value of $i$?  Please include all the decimal places in your answer.

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[[1]]

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What is the value of $A$?  Please give your answer to the nearest cent.

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€[[2]]

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", "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "gaps": [{"allowFractions": false, "variableReplacements": [], "maxValue": "n2+0.00001", "minValue": "n2-0.00001", "variableReplacementStrategy": "originalfirst", "correctAnswerFraction": false, "showCorrectAnswer": true, "scripts": {}, "marks": 1, "type": "numberentry", "showPrecisionHint": false}, {"allowFractions": false, "variableReplacements": [], "maxValue": "int2+0.00001", "minValue": "int2-0.00001", "variableReplacementStrategy": "originalfirst", "correctAnswerFraction": false, "showCorrectAnswer": true, "scripts": {}, "marks": 1, "type": "numberentry", "showPrecisionHint": false}, {"allowFractions": false, "variableReplacements": [], "maxValue": "A2+0.05", "minValue": "A2-0.05", "variableReplacementStrategy": "originalfirst", "correctAnswerFraction": false, "showCorrectAnswer": true, "scripts": {}, "marks": 1, "type": "numberentry", "showPrecisionHint": false}], "showCorrectAnswer": true, "scripts": {}, "marks": 0, "type": "gapfill"}], "extensions": [], "statement": "

Two rival high street banks offer customers a new deposit account.

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Bank A offers an account that earns interest at a rate of $\\var{perc1}$% per annum where interest is compounded annually.

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Bank B offers an account that earns interest at a nominal rate of $\\var{perc2}$% per annum where interest is compounded daily.

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Suppose that a potential customer has €$\\var{P}$ to invest for $\\var{n1}$ years.    

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The compound interest formula is:

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$\\ A = P(1+i)^n $

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You may assume that there are 365 days per annum.

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Compare two savings accounts with different interest rates.

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rebelmaths

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