Finance Interest Problems

Interest problems ask you to track how money grows or how debt accumulates over time. You'll work with simple interest (a fixed amount each period) and compound interest (interest earning interest), and the difference between the two is where most of the learning happens. A savings account growing at 4% compounded monthly behaves very differently from one earning 4% simple interest, and these problems teach you to quantify that difference. You'll also encounter loan amortization, comparing investment options, and figuring out how long it takes to double your money. This is one of the most directly practical categories — you'll use these skills every time you evaluate a mortgage, a car loan, or a retirement plan.
Maximum House Price from Monthly Payment

Calculate max home price using $1,450/month mortgage at 8% over 30 years. Uses present value of annuity formula.

Projectile Motion: When Does Ball Hit Ground?

A ball is thrown from 6.5 ft at 147 ft/sec. Use h(t)=-16t²+147t+6.5=0 to find when it lands. Quadratic formula explained.

Projectile Motion: Bread Toss Height Equation

Write kinematic equation for vertical position. Find time for bread to reach 16 meters. Quadratic and substitution methods.

Projectile Motion: Package Drop Distance

Plane travels 81 m/s at 125 m height. Calculate horizontal distance package travels before landing using kinematic equations.

Quadratic Equations: Ball Toss Height

Find when 96 ft/s thrown ball reaches 48 ft using quadratic kinematic formula. Round to nearest tenth.

Simple vs Compound Interest

Sam's simple interest vs Colin's compound interest: both invest $16,000, same amount after 2 years. Solve for r.

Tour Company Profit Function

Build revenue, cost, and profit functions for a tour company. Practice linear modeling with fixed and variable expenses.