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The Tian2 Study Library AP Edition · Tian2 Editorial Bureau
Volume I · MMXXVI AP Business with Personal Finance
Library AP Business with Personal Finance Unit 3: Personal Saving and Borrowing + Business Finance and Accounting
⁂   AP Business with Personal Finance · Unit 3 · ~35 periods

3. Personal Saving & Borrowing
+ Business Finance & Accounting

The highest-weighted unit on the exam: compound interest, credit scores, the three core financial statements (income statement, balance sheet, cash flow), equity vs. debt financing, and GAAP ethics. A 4-function calculator is permitted — know which formulas to apply.

~35 instructional periods 25–35% of AP Exam MCQ Calculator permitted (4-function)

Part 1: Personal Saving and Borrowing

Savings Vehicles

  • High-Yield Savings Account (HYSA): FDIC-insured bank account paying higher interest than a standard savings account. Fully liquid — funds accessible at any time. Appropriate for emergency funds and short-term savings goals.
  • Certificate of Deposit (CD): Bank deposit for a fixed term (3 months to 5 years) at a guaranteed interest rate. Higher interest than HYSA but funds are locked — early withdrawal incurs a penalty. Appropriate when you know you will not need the funds before maturity.
  • Opportunity cost of saving: Choosing to save money instead of spending it means forgoing the consumption value of that spending. Choosing to spend means forgoing future interest earnings. Both decisions have an opportunity cost.

Compound Interest

Compound interest earns interest on previously earned interest, causing savings to grow exponentially over time.

$$A = P\!\left(1 + \frac{r}{n}\right)^{nt}$$

where $P$ = principal, $r$ = annual interest rate (decimal), $n$ = number of compounding periods per year, $t$ = years, and $A$ = final amount.

Example: $1,000 at 5% annual rate, compounded monthly, for 3 years:

$$A = 1000\!\left(1 + \frac{0.05}{12}\right)^{12 \times 3} = 1000 \times (1.004167)^{36} \approx \$1{,}161.62$$

Simple interest (for comparison): $A = P(1 + rt) = 1000(1 + 0.05 \times 3) = \$1{,}150.00$. The difference ($11.62) represents the compounding effect over 3 years — small here, but significant over decades.

Credit and Debt

Credit score (300–850): A numerical representation of creditworthiness based on payment history (35%), amounts owed (30%), length of credit history (15%), new credit (10%), and credit mix (10%). Higher scores unlock lower interest rates on loans.

Types of credit:

TypeCharacteristicsTypical APR range
Credit cardRevolving credit; pay minimum or in full each month; high APR if balance carried18–29%
Personal loanFixed term, fixed payment, typically unsecured8–20%
Auto loanSecured by the vehicle; lower rate than unsecured5–12%
MortgageSecured by the property; longest term (15–30 years); lowest rate of consumer credit4–8%

Debt-to-income (DTI) ratio: Monthly debt payments ÷ gross monthly income. Lenders use DTI to assess repayment capacity. A DTI above 43% typically disqualifies a borrower for most mortgages.

Debt management strategies: The avalanche method pays minimum on all debts and directs extra funds to the highest-interest debt first (mathematically optimal — minimizes total interest paid). The snowball method pays minimum on all debts and directs extra funds to the smallest balance first (psychologically motivating — faster early wins).

Part 2: Business Finance and Accounting

Startup vs. Operating Costs

  • Startup costs: One-time costs to get the business running — equipment purchase, legal fees, initial inventory, website build, licenses. Incurred before revenue begins.
  • Operating costs: Ongoing costs to run the business — rent, salaries, utilities, raw materials, marketing. Recurring expenses that appear on the income statement.
  • Fixed costs: Do not change with production volume (rent, insurance, salaried employees).
  • Variable costs: Change directly with production volume (raw materials, hourly labor, shipping).

Sources of Capital: Equity vs. Debt Financing

FeatureEquity financingDebt financing
SourceInvestors (angel investors, venture capital, selling shares)Lenders (banks, bonds, SBA loans)
RepaymentNo fixed repayment obligation — investors share in future profitsFixed repayment schedule with interest
Ownership impactDilutes owner's ownership percentageNo dilution — owner retains full ownership
Risk to businessLower — no default risk if business underperformsHigher — missed payments can trigger default
Investor/lender focusGrowth potential, market size, team qualityCash flow, collateral, credit history, DTI

The Three Financial Statements

Exam trap — know which statement answers which question:

  • Is the business profitable? → Income Statement
  • What does the business own and owe right now? → Balance Sheet
  • Does the business have enough cash to pay its bills? → Cash Flow Statement

Income Statement

Reports revenue, expenses, and profit over a period of time (month, quarter, year).

$$\text{Gross Profit} = \text{Revenue} - \text{COGS}$$

$$\text{Operating Income} = \text{Gross Profit} - \text{Operating Expenses}$$

$$\text{Net Income} = \text{Operating Income} - \text{Taxes} - \text{Interest}$$

COGS (Cost of Goods Sold) = direct costs of producing the goods sold (raw materials, direct labor). Operating expenses = indirect business costs (rent, marketing, administrative salaries).

Balance Sheet

Reports what the business owns and owes at a single point in time. The fundamental accounting equation:

$$\text{Assets} = \text{Liabilities} + \text{Owner's Equity}$$

  • Assets: What the business owns. Current assets (cash, accounts receivable, inventory — converted to cash within 1 year) + Long-term assets (equipment, real estate, intangibles).
  • Liabilities: What the business owes. Current liabilities (accounts payable, short-term loans — due within 1 year) + Long-term liabilities (mortgages, long-term debt).
  • Owner's Equity: The residual claim after liabilities are subtracted from assets — what owners would receive if the business were liquidated and all debts paid. Net Worth = Assets − Liabilities.

Cash Flow Statement

Reports actual cash inflows and outflows over a period, organized into three activities:

  • Operating activities: Cash from the core business — customer payments received, supplier payments made, employee salaries paid. This is the most important indicator of business health.
  • Investing activities: Cash from buying or selling long-term assets — purchasing equipment, acquiring another business, selling property.
  • Financing activities: Cash from borrowing or repaying debt, issuing or buying back shares, paying dividends.

Key insight: A business can be profitable (positive net income on the income statement) while simultaneously running out of cash (negative operating cash flow) — for example, if customers are slow to pay their invoices. The cash flow statement reveals this gap that the income statement hides.

Key Financial Ratios

RatioFormulaWhat it measures
Profit marginNet Income ÷ RevenueWhat percentage of each revenue dollar becomes profit
Current ratioCurrent Assets ÷ Current LiabilitiesAbility to pay short-term obligations (above 1.0 = positive)
Debt-to-equityTotal Liabilities ÷ Owner's EquityFinancial leverage; how much debt vs. owner investment funds the business

GAAP and Financial Ethics

Generally Accepted Accounting Principles (GAAP) are standardized rules for financial reporting that ensure consistency, comparability, and reliability across businesses. Key principles include:

  • Revenue recognition: Revenue is recorded when earned (goods delivered/services rendered), not when cash is received.
  • Matching principle: Expenses are recorded in the same period as the revenue they helped generate.
  • Consistency: Same accounting methods used year-to-year; changes must be disclosed.

Fraudulent financial reporting — inflating revenue, hiding liabilities, misclassifying expenses — misrepresents the business's true financial position to investors and lenders, causing market harm and triggering regulatory consequences (SEC enforcement, criminal prosecution).

Worked Practice: Financial Statement Analysis

Original Practice · Tian2 AP (FRQ 2 style — Personal Finance)

Scenario: Jordan earns $4,500/month gross income. Monthly expenses: rent $1,100, car payment $350, credit card minimum payment $85, groceries $300, utilities $120, streaming services $40. Jordan has a credit card balance of $3,200 at 22% APR and a student loan balance of $8,500 at 5.5% APR.

(A) Calculate Jordan's debt-to-income (DTI) ratio using monthly debt payments.

Monthly debt payments = car payment ($350) + credit card minimum ($85) = $435. DTI = $435 ÷ $4,500 = 0.097 = 9.7%. (Note: groceries, utilities, and streaming are expenses, not debt payments — do not include them in DTI.)

(B) Jordan has $200/month available after all expenses to apply to debt repayment. Identify which debt repayment strategy — avalanche or snowball — would minimize total interest paid, and explain why.

Avalanche method. Jordan should direct the extra $200 to the credit card debt (22% APR) first because it carries the higher interest rate. Paying off the higher-rate debt faster reduces the total amount of interest accrued over time — every dollar applied to the credit card saves 22 cents per year in future interest, versus only 5.5 cents if applied to the student loan. The snowball method (paying the smaller balance first) would target the credit card anyway in this case since $3,200 < $8,500, but if the balances were reversed, the avalanche would diverge from the snowball and save more interest.