Difficulty: Medium
Correct Answer: $15,615.52
Explanation:
Introduction / Context:
This is a simple interest “exact time” problem. Even though the duration is stated as seven months, the problem explicitly guides us to use exact days from April 7 to November 7. Under exact simple interest, we use t = (number of days) / 365. Then interest I = P * r * t, and total amount repaid A = P + I. This tests correct time conversion and careful substitution without compounding.
Given Data / Assumptions:
Concept / Approach:
Use exact simple interest:
I = P * r * t
t = 214/365
Then compute total repayment:
A = P + I
Step-by-Step Solution:
t = 214/365
I = 15000 * 0.07 * (214/365)
First compute: 15000 * 0.07 = 1050
So, I = 1050 * (214/365)
I ≈ 615.52 (rounded to cents)
A = 15000 + 615.52 = 15615.52
Verification / Alternative check:
If you used a rough 7/12 year estimate, interest would be close to 612.50, which is very near the exact-days result. The exact-days method gives a slightly different number because the actual day count is 214/365 ≈ 0.5863 years.
Why Other Options Are Wrong:
$14,615.52 and $13,615.52 incorrectly reduce principal by $1,000 or $2,000. $16,615.52 adds an extra $1,000 not justified by the interest. $15,500 is too low for 214 days at 7% on $15,000.
Common Pitfalls:
Using 7 months as 7/12 without considering exact days when asked, using 360-day year when 365 is specified, or accidentally compounding monthly.
Final Answer:
The total amount to be repaid is $15,615.52.
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