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.Write and solve the exponential equation 3^h = 6,561 to find when algae reaches that population.
Bacteria double every 5 minutes. Find when population reaches 16 and 64 cells. Exponential models.
Skull has 20% of original C-14. Half-life = 5730 years. Estimate age using radioactive decay formula.
Find centripetal acceleration and chain tension for a rotating hammer. Convert rev/s to angular velocity.
A company gains 10% customers per quarter starting at 1,500. Find total after 100 quarters.
Calculate compound interest (daily) and effective annual interest rate using the compound interest formula.
Find annual house appreciation rate (1985–2005), then predict 2010 value. Exponential growth problem.
Find when population density reaches 1 person per square yard using exponential growth. 4.9% annual rate, 4.9M initial population.
Use kinematic equations to find vertical separation when a falling pot has different speeds at two heights.
Solve two-account investment problems. Find allocation between CD and bonds using system of equations.