Interest: Simple Interest
A "Double Your Money" scheme at a bank doubles the savings of customers depositing money by offering a 10% annual simple payment on the original deposit. How many years will it take Sally to double her money if she makes a $450 deposit and makes no further deposits or withdrawals from the account?
Incorrect.
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Incorrect.
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Incorrect.
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Incorrect.
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Correct.
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In order to double the principal amount, Sally needs to earn $450 in interest. Based on this, the time needed to double the money can be calculated as follows:
>$$\text{Simple interest} = \text{Principal} \times \text{Interest rate} \times \text{Time}$$
>$$\displaystyle \$450 = \$450 \times 0.1 \times \text{Time}$$
>$$ 450 = 45 \times \text{Time}$$
>$$\displaystyle \text{Time} = \frac{450}{ 45}$$
>$$\text{Time}= 10 \text{ years}$$
2
5
10
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45
