Plugging In: Using Good Numbers

Jane deposited half as much as Susan in her bank account. Both accounts earn simple interest. If Jane and Susan earned the same amount of interest at the end of the year and Susan's bank account pays $$p\%$$ annual interest, what is the interest rate for Jane's account?

Incorrect. [[Snippet]]

Incorrect. [[Snippet]]

Incorrect. [[Snippet]]

Incorrect. [[Snippet]]

Correct. [[Snippet]] Plug in $200 for Susan's deposit and 10% for $$p$$. Based on this, interest earned by Susan is $20 (10% of 200 = 20). Since Jane's deposit is half of Susan's, Jane deposited $100 and needs to earn $20 in interest. >$$\text{Jane's rate} = \frac{20}{100} \times 100 = 20\%$$ That's your goal. Plug in $$p=10$$ into the answer choices, and __POE__ anything that does not match your goal. Since all of the other answer choices do not match 20 for $$p=10$$, this is the correct answer.

$$2p \%$$

$$p \%$$

$$ \frac{2p}{3} \%$$

$$ \frac{p}{2} \%$$

$$ \frac{p}{3} \%$$