In interest calculations, the method that uses a 365-day year for day-count when computing simple interest is called what?

Introduction / Context:
Engineering economics distinguishes between different day-count conventions for simple interest. The choice affects the computed interest for partial-year periods and must match contract terms. Two common conventions are the 360-day (banker’s) year and the 365-day (calendar) year.

Given Data / Assumptions:

• Simple interest I = P * i * (days / base_year_days).
• Base year days may be 360 or 365 depending on convention.
• Question asks for the term corresponding to the 365-day basis.

Concept / Approach:

Exact simple interest uses the actual number of days over 365 (or 366 in leap years by some contracts). Ordinary simple interest uses a 360-day year. Correct identification ensures consistent valuation of short-term notes and claims.

Step-by-Step Solution:

Verification / Alternative check:

Finance references and contract templates state these conventions explicitly; calculators and spreadsheets offer exact/ordinary settings for day-count.

Why Other Options Are Wrong:

• 'interest': Non-specific.
• Ordinary simple interest: 360-day year, not 365.
• Compound exact interest: Not a standard simple-interest term.

Common Pitfalls:

• Mismatched day-count between lender and borrower causing reconciliation issues.

Final Answer:

exact simple interest