01
Units and estimation
Define the central objects, connect at least two representations, solve direct and unfamiliar applications, and explain how the result can be checked.
Goal: recognise a units and estimation problem from its wording, carry out the governing method, and check that the result is reasonable.
02
Linear models
Connect formulas, tables, and graphs; identify domain and parameters; then interpret how changing an input or coefficient changes the output.
Goal: recognise a linear models problem from its wording, carry out the governing method, and check that the result is reasonable.
03
Growth and decay
Translate between exponential and logarithmic forms, identify the base and rate, and interpret parameters and domain in the original context.
Goal: recognise a growth and decay problem from its wording, carry out the governing method, and check that the result is reasonable.
04
Optimization
Relate local change to slope, apply the appropriate derivative rule, and use sign, units, and graph behavior to interpret the result.
Goal: recognise a optimization problem from its wording, carry out the governing method, and check that the result is reasonable.
05
Regression models
Connect formulas, tables, and graphs; identify domain and parameters; then interpret how changing an input or coefficient changes the output.
Goal: recognise a regression models problem from its wording, carry out the governing method, and check that the result is reasonable.
06
Model validation
Connect formulas, tables, and graphs; identify domain and parameters; then interpret how changing an input or coefficient changes the output.
Goal: recognise a model validation problem from its wording, carry out the governing method, and check that the result is reasonable.
Mathematical Modeling questions with worked answers
These 8 questions are printed in full on this page and are drawn across all 6 course units. Nothing here is generated on the fly. Cover the options, solve each one on paper, and only then open the worked answer to compare your method with the one shown.
Question 1: Convert 90 kilometers per hour into meters per second.
Mathematical Modeling · Units and estimation
- 25 m/s
- 324 m/s
- 1.5 m/s
- 50 m/s
Show the worked answer
- One kilometer is 1,000 meters, so 90 km is 90,000 meters.
- One hour is 3,600 seconds.
- Divide: 90,000 / 3,600.
- 90,000 / 3,600 = 25, so the speed is 25 meters per second.
Answer: 25 m/s
Question 2: A dispenser holds 15 liters. How many 250 milliliter cups can it fill?
Mathematical Modeling · Units and estimation
- 60 cups
- 6 cups
- 600 cups
- 37 cups
Show the worked answer
- Put both amounts in the same unit. 15 liters is 15 x 1,000 = 15,000 milliliters.
- Each cup takes 250 milliliters.
- 15,000 / 250 = 60.
- So the dispenser fills 60 cups.
Answer: 60 cups
Question 3: A rental costs $45 plus $0.28 per mile. What does a 120 mile trip cost?
Mathematical Modeling · Linear models
- $78.60
- $33.60
- $45.28
- $87.60
Show the worked answer
- The model is cost = 45 + 0.28m, where m is miles.
- The mileage charge is 0.28 x 120.
- 0.28 x 120 = 33.60.
- 45 + 33.60 = 78.60, so the trip costs $78.60.
Answer: $78.60
Question 4: A substance has a half-life of 12 years. If 80 grams are stored, how much is left after 36 years?
Mathematical Modeling · Growth and decay
- 10 grams
- 20 grams
- 26.7 grams
- 5 grams
Show the worked answer
- 36 years is 36 / 12 = 3 half-lives.
- After one half-life: 80 / 2 = 40 grams.
- After two: 40 / 2 = 20 grams.
- After three: 20 / 2 = 10 grams.
Answer: 10 grams
Question 5: A farmer fences a rectangular pen against a straight wall using 60 m of fence on the other three sides. What is the largest possible area?
Mathematical Modeling · Optimization
- 450 square m
- 225 square m
- 400 square m
- 900 square m
Show the worked answer
- Let the two sides at right angles to the wall each be y, and the side parallel to the wall be x, so x + 2y = 60.
- Then x = 60 - 2y and the area is A = y(60 - 2y) = 60y - 2y^2.
- This parabola opens downward, so the maximum is at y = -60 / (2 x -2) = 15.
- Then x = 60 - 30 = 30, and the area is 30 x 15 = 450 square m.
Answer: 450 square m
Question 6: A regression line is y = 2.4x + 11. At x = 25 the measured value is 68. What is the residual?
Mathematical Modeling · Regression models
- -3
- 3
- 71
- -71
Show the worked answer
- First predict: 2.4 x 25 = 60, and 60 + 11 = 71.
- A residual is the observed value minus the predicted value.
- 68 - 71 = -3.
- The negative sign means the model predicted too high at that point.
Answer: -3
Question 7: A linear model reports R-squared = 0.85. What does that mean?
Mathematical Modeling · Model validation
- The model explains 85% of the variation in the response.
- 85% of the predictions are exactly correct.
- The slope of the line is 0.85.
- The model will be right 85% of the time on new data.
Show the worked answer
- R-squared compares the variation the model explains with the total variation in the data.
- 0.85 means 85 out of every 100 units of variation are accounted for by the model.
- The remaining 15% is variation the model does not capture.
- R-squared says nothing about how many single predictions are exactly right, and nothing on its own about new data.
Answer: The model explains 85% of the variation in the response.
Question 8: A town of 8,000 people grows 3% each year. What is the population after 10 years, to the nearest person?
Mathematical Modeling · Growth and decay
- 10,751
- 10,400
- 8,240
- 16,000
Show the worked answer
- A 3% yearly rise multiplies the population by 1.03 each year.
- After 10 years the population is 8,000 x 1.03^10.
- 1.03^10 is about 1.343916.
- 8,000 x 1.343916 = 10,751.33, so about 10,751 people.
Answer: 10,751
Which unit each printed question belongs to
Use this map after marking your work. If two misses share a unit, review that unit before starting a generated set.
How the generated Mathematical Modeling sets are created
The 8 questions above are fixed and checked. The generator at the top of the page is different: it writes fresh questions with AI from the course and unit information shown here, then the application checks each one for a complete prompt, four choices, one keyed answer, and an explanation. Generated questions are original practice—not official or released exam questions—and AI can still make mathematical mistakes. Verify a disputed answer with the stated method, your course materials, or the MathGPT solver, and follow the site's academic-integrity guidance.
Questions about this Mathematical Modeling practice page
What does this page cover?
It covers all 6 Mathematical Modeling units listed above. Choose one unit for focused work, or mixed review to test method selection, and switch to test mode when you want all units mixed under time.
When can I see correct answers and explanations?
The 8 printed questions on this page keep their worked answers behind a toggle, so you can check any one of them straight away. In the generator above, practice mode explains each question as soon as you answer it, while test mode holds every explanation until you submit.
What should I do with a missed question?
Classify the miss as a definition, setup, calculation, interpretation, or timing error. Re-solve it from a blank page, then use the MathGPT tutor for a hint or method check.